houseplan-card/docs/ARCHITECTURE.md

House Plan architecture

Updated: 2026-08-10 (v1.61.0-beta.3). The repository = a HACS integration (category Integration) that contains both the backend (custom_components/houseplan) and the Lovelace card (src/ → dist/).

Layout

houseplan-card/
├─ src/                          # card sources (TypeScript + Lit 3)
│  ├─ houseplan-card.ts          # the card: rendering, states, drag, tooltip, sticky header
│  ├─ hp-dialog.ts               # shared HA/native modal shell and focus lifecycle
│  ├─ editor-secondary.ts        # context tray model, groups, focus/dismiss lifecycle and stable template
│  ├─ editor-secondary.styles.ts # styles owned by the context tray/submenu surface
│  ├─ render/opening-tunnels.ts  # immutable SVG projection of resolved tunnel geometry/fills
│  ├─ editor.ts                  # GUI config editor (ha-form + selectors)
│  ├─ rules.ts                   # icon rules (iconFor), filtering, groups, fallback order
│  └─ data/
│     ├─ house.ts                # geometry: ROOMS (rooms→area), FLOOR_VB (viewBox), names
│     └─ backgrounds.ts          # VECTOR plans (SVG base64) + FLOOR_BG_RECT (positioning)
├─ dist/houseplan-card.js        # build (rollup+terser), ~290 KB, plans embedded
├─ demo/golden/                  # deterministic HP-QA-01 matrix, capture/verify/accept
├─ demo/performance/             # large-house budgets and same-runner comparison
├─ scripts/release-*.mjs         # exact-SHA publication contract and local orchestrator
├─ .github/workflows/
│  └─ publish-prerelease.yml     # draft-first one-button prerelease publication
├─ custom_components/houseplan/  # the HA integration
│  ├─ __init__.py                # setup: Store, WS commands, JS serving (add_extra_js_url)
│  ├─ trails.py                  # server-side vacuum trail recorder (state-change driven)
│  ├─ websocket_api.py           # houseplan/layout/get|set|update
│  ├─ config_flow.py             # single entry; admin_only option (editing restricted to admins)
│  ├─ const.py                   # DOMAIN, STORAGE_KEY, VERSION, FRONTEND_URL
│  └─ frontend/houseplan-card.js # copy of dist, served as /houseplan_files/houseplan-card.js
├─ hacs.json                     # HACS manifest
└─ docs/                         # this documentation

Rollup embeds a source fingerprint in the bundle. Performance and golden-image tooling compares it with the current src/ tree before recording results, so a committed demo snapshot from an older source revision cannot produce a false baseline.

Prerelease publication has one fail-closed contract shared by the local command and the manual GitHub workflow. The tag version must match all six shipped version authorities, both changelogs need a dated section, and the canonical bilingual docs/RELEASE-NOTES.md must link to immutable tagged changelogs. A public release is assembled as a draft, receives and verifies houseplan-card.js plus houseplan.zip, and becomes visible only after the exact candidate SHA has a green Validate. Existing release-event workflows are kept as an independent recovery path; they enforce the same exact-SHA gate. Validate contains only the candidate performance smoke so ordinary betas do not wait for a full comparison. Every main promotion starts the dedicated performance.yml workflow; stable release assets additionally require that workflow to be green for the exact tagged SHA. Weekly and manual full runs keep the same profiler available between stable promotions.

Key decisions

1. One repository — integration + card. The integration serves the JS (async_register_static_paths) and registers it as a Lovelace resource (module) — the frontend waits for resources before rendering, so the card also works on a cold start of the mobile app (unlike add_extra_js_url, which remains a fallback for YAML mode). The user does not need to add the resource manually.
2. Icon layout lives on the server. helpers.storage.Store(1, "houseplan.layout") → .storage/houseplan.layout. The card reads/writes via hass.callWS (houseplan/layout/get|set|update). Fallback — localStorage (when the integration is absent).
3. No token. Everything comes from the frontend hass object and its authenticated connection: hass.states is reactive, while a module-level ha-binding-status cache obtains the complete device/entity registries via hass.callWS. There is one fetch/in-flight request and one pair of registry subscriptions per HA connection, shared by every full/static card on the page; House Plan creates no direct socket or token. Newly observed rows in the live frontend projection augment an older full snapshot immediately, and a changed projection schedules a debounced full reconciliation. This keeps discovery and disabled_by changes reactive even when a registry event subscription is unavailable.
4. Reactivity. Every state change in HA leads to set hass → re-render. Temperatures/LQI/on-off are live by definition (verified by substituting state).
5. One modal contract. Card modals render through hp-dialog. In Home Assistant it delegates surface semantics and trapping to ha-dialog; the standalone demo falls back to native <dialog>. The wrapper owns the title, initial focus, Escape close event and restore-focus session. Focus sessions are scoped to a card shadow root so nested dialogs return to their parent trigger and dialog replacement still returns to the original outside opener. Its footer wrapper is a full-width slot item: HA lays the footer slot out as flex, so flattening that wrapper would shrink action rows to their content.

Coordinate system

• Base space: 1489×1053 ("pixels" of the old PNG render, 1 unit = 1 px). All rooms, icon positions and floor viewBoxes live in it. DO NOT change without a layout migration.
• Vector plans are inserted as <image href=svg> into the FLOOR_BG_RECT rectangle:
  • f1: scale 0.647, offset (490, 27) → rect [490, 27, 774.2, 949.3]
  • f2: scale 0.896, offset (351, 21) → rect [351, 21, 1048.4, 961.4]
  • computed via raster correlation (cv2.matchTemplate on binarized darkness maps) of the SVG render against the reference PNG; accuracy ~1 px. The scripts are reproducible (docs/DEVELOPMENT.md).
• Rooms (ROOMS) are snapped to the inner faces of walls (semi-automatic: search for the nearest "dark line" along the profile + manual fine-tuning against overlay renders).

Card data model (runtime)

DevItem: id (device_id), name, model, area, floor, icon, entities[], primary (the first resolved state entity for actions requiring one target), temp, members[] (light group), link/linkPrimary (Z2M group). Marker state consumes the complete resolved role, not this single compatibility field. entities[] contains active runtime entities only; allEntities[] is metadata-only, and bindingStatus distinguishes active, ha_disabled, orphaned and unverified without mutating persisted markers.

resolveHaBindingStatus() is the only authority for saved HA bindings. Full registry data wins; a limited-permission client accepts positive live evidence but never guesses that a missing shortened row means disabled/deleted. Every plan-level consumer uses the active registry/state projection, so disabled bindings cannot leak through Glow, climate, LQI, live text, openings, controls or vacuum rendering. A bounded local runtime cache stores only the last authoritative active/disabled decision to avoid a stale warm-remount flash; it is not part of the server config or layout.

Built from the registries (_buildDevices), rules carried over 1-to-1 from the prototype:

• only devices with an area from the room list are shown;
• hidden: entry_type=service, integrations from EXCLUDED_DOMAINS, model=Group, scenes, bridges, myheat sub-devices, duplicates by "name|area";
• a device with a lock.* entity always gets mdi:lock (TTLock locks in the registry are named "Dom"/"Terrasa"/"Kladovka" [House/Terrace/Storeroom] — unrecognizable by name);
• lamps (mdi:lightbulb) with ≥2 in a room collapse into a group mdi:lightbulb-group (click → menu: the whole group + individual lamps).

Live data

• Temperature: an entity with device_class=temperature / °C / _temperature$ → label on the right.
• LQI (zigbee): the average over *_linkquality entities → label under the icon; color via lqiColor(): ≤40 red → ≥180 green (hsl gradient). The room average is shown in the room tooltip. The same tooltip includes the formatted clean-floor area (inner contour for thick walls), and View hover gives every room an accent/brightness highlight.
• Icon state classes: on (yellow), open (orange: cover/valve/lock/binary_sensor of problem classes), unavail (transparency, also used by a powered-down media endpoint). Yellow remains on the marker in source-glow fill mode: a light pool is spatial information, not a replacement for the universal working-state plate.

Vacuum telemetry authority

src/vacuum.ts owns pure normalization and arbitration. Telemetry paths are always Pt[][]; non-drawable segments are discarded before the 64-segment and 4000-point budgets, and the renderer emits one SVG path with independent M commands. resolveCurrentVacPath() is the only integration → server → local priority decision. resolveVacSource() is sticky for saved sources and limits automatic selection to compatible entities on the same HA device; the card adds registry status through the shared resolveHaBindingStatus() authority.

Room auto-calibration uses the same shoelace areaCentroid() for plan polygons and robot outlines. Residuals are converted through resolved grid pitch and cell centimetres; matrices above the 40 cm threshold remain proposals until an explicit UI decision. trails.py owns persistent current/previous runs and a refresh-time (marker, source) health state whose missing/disabled reason is mutable and warning-deduplicated.

Sizes

icon_size in the config = % of the visible plan area width (default 2.5). Implementation: .stage { container-type: inline-size } + sizes in cqw. Legacy px values (>8) are ignored.

Sticky header

.head { position: sticky; top: var(--header-height, 56px) }; it is MANDATORY that ha-card { overflow: visible } — overflow: hidden breaks sticky.

Device markers (v1.6.0+)

Per-marker appearance: display: badge|icon_ripple|value|static_icon. Entity semantics originate in src/device-visual.ts; src/device-presentation.ts resolves the complete renderer-ready projection (sources, value, icon, classes, metrics and explanation), and src/device-face.ts renders that projection on the full plan, device preview and static space card. badge shows the icon/morph and status plate; icon_ripple additionally shows a finite event, static presence, mechanical transition or actual-work ring; value replaces the icon with the HA-formatted numeric or text value. Ambiguous/missing/unavailable sources fall back to the icon instead of selecting an arbitrary registry row. A critical alarm is red in every dynamic presentation. static_icon deliberately keeps the configured/automatic base icon on one neutral dark plate: state morphing, work/open/alarm/unavailable paint, activity, RGB, value, temperature/humidity/LQI badges and live vacuum overlays are all suppressed. Hover/focus, taps, controls and light aggregation keep their normal behaviour. normalizeDeviceDisplay() is the mandatory compatibility gate for every consumer and maps legacy ripple to icon_ripple. The marker dialog builds its unsaved draft through buildDevices, then hp-device-preview shows the actual projection, integration provenance from registry/config-entry metadata and an isolated 3.3 s activity demonstration. Runtime baselines are seeded as soon as a rebuilt registry becomes authoritative, before the next HA snapshot is classified; source-key changes reset any finite effect immediately. The backend accepts legacy display: ripple only for compatibility. ripple_color and ripple_size remain the stored names for the ordinary activity effect. size (icon multiplier via the --dev-size CSS var — value badges scale along) and angle rotate/scale a single icon. Room drawing shows a live ruler (segmentCm + formatLength, metres or feet+inches by hass.config.unit_system); the scale is per-space cell_cm (default 5 cm per grid cell).

config.markers[]: {id, binding:'device:<id>'|'entity:<eid>'|'virtual', space?, area?, hidden?, removed?, name?, icon?, model?, link?, description?, pdfs:[{name,url}]}. A hybrid: auto-discovered HA devices appear on their own; a marker with binding=device:<id> overrides them (metadata/rebinding/hiding), entity:<eid> — for groups/helpers, virtual — a manual icon without HA. The marker id = device_id / lg_<eid> / v_<rand> (preserves the position in the layout). The binding picker excludes already-placed references and duplicates by name|area. Manual files: transactional HTTP upload into <config>/houseplan/files/<id>/ (staging up_* folders promoted on save), served via signed /api/houseplan/content/files/… urls.

removed:true is a binding tombstone, not a renderable marker. It claims an HA binding against automatic discovery while intentionally exposing that same binding to the Add picker. A device tombstone excludes all data of that device; an entity tombstone excludes the standalone entity binding but does not mutate the same entity out of a still-live parent device. Runtime-filtered references such as controls remain persisted and become active again after re-add. Re-adding replaces the tombstone; virtual markers need no tombstone because they have no discovery source.

Server-side configuration (current shape, v1.51+)

Persisted colour boundary

Every colour stored in Houseplan config has exactly one representation: #RRGGBB (case-insensitive hexadecimal digits, no whitespace or CSS functions). src/color.ts owns the frontend resolver and custom_components/houseplan/validation.py::_COLOR owns the write schema. Resolvers apply a safe default again at render time because an old, imported or manually edited store is returned without a destructive read migration.

Home Assistant rgb_color is live state rather than persisted user input. It is accepted only as three finite numeric channels, clamped/rounded to 0–255 and emitted by the application as canonical rgb(R, G, B). The final inline-style boundary accepts only stored hex or that generated form. Supporting arbitrary CSS colour syntax would require a separate product/security decision; it must not be added to an individual sink.

.storage/houseplan.config (Store):

{ "spaces": [{ "id","title","plan_url","plan_aspect",
               "plan_x","plan_y","plan_scale_x","plan_scale_y","plan_angle",
               "plan_scale",   // legacy optional fallback, docs/BACKDROP.md
               "view_box":[4],
               "rooms":[{"id","name","area","poly|x/y/w/h","open_to","settings"}],
               "room_drafts":[…], "partitions":[…], "wall_columns":[…],
               "openings":[…], "decor":[…], "settings":{…} }],
  "markers": [{ "id","binding":"device:<id>|entity:<eid>|virtual","hidden","removed",
                "name","icon","display","controls","is_light","glow_color","tap_action",
                "room_id","pdfs",… }],
  "settings": { "exclude_integrations":[], "group_lights":true,
                "filter_seeded":true, "fill_colors":{…}, "icon_rules":[…],
                "known_devices":[…], "new_device_ids":[…] } }

All coordinates are normalized (0..1 of the canvas); the canvas is always square (v1.48.0), render space NORM_W × NORM_W (1000×1000). A space has no proportions of its own — plan_aspect is the IMAGE's ratio, used to letterbox it centred on the square; optional plan_x/y, independent plan_scale_x/y and plan_angle then transform that rectangle (planRect, docs/BACKDROP.md). Legacy plan_scale feeds both axes, and the absence of every transform field is the centred default exactly. The schema bounds geometry to ±5000 with strictly positive sizes (HP-1501/1502). device_overrides/virtual_devices are long gone — markers carry everything. marker.hidden is the explicit reversible "hide from plan" flag seeded once by the old filter; marker.removed is the minimal delete tombstone (docs/FILTERING.md). Layout v2: {device_id | rl_<roomId>: {"s": space, "x", "y"}} (normalized, bounded ±5000). Plan files: <config>/houseplan/plans/<space>.<token>.<ext> (copy-on-write, never overwritten), served via signed /api/houseplan/content/plans/_/<name> urls; growth is bounded by store quotas, nothing is ever deleted for being old (docs/SCOPE.md).

Room and independent wall geometry

Room-boundary walls remain derived from room outlines (roomEdges, deduped by segKey), so deleting a room keeps the boundaries its neighbours still contribute. Three explicitly typed exceptions are stored per space: room_drafts for persisted unfinished room outlines, partitions for one-segment independent walls and wall_columns for square/circular columns. They do not create a room or HA area and never split a room implicitly. Their physical bodies are unioned with room walls for rendering and light occlusion, and subtracted from clean room floor area. Openings (doors, windows and gates) still belong only to derived room walls and never cut an independent object.

Rooms may not overlap (pointStrictlyInside + roomsOverlap; being ON a shared wall is legal — real neighbouring walls overlap collinearly rather than match exactly). Merge/Split use boolean geometry from polyclip-ts (chosen over polygon-clipping, whose ESM build exports only a default while its types declare named exports — breaking either tsc or the runtime): merge accepts a pair only when the union collapses into one hole-free outline; split cuts wall-to-wall with a chord, the bigger part keeps the room identity (name/area/devices).

Markup editor (v1.4.0+)

State inside the card: _markup (mode), _tool (draw/partition/column/merge/split/resize/opening/ boundary/wallthick/delroom), _path (the current outline, vertices on the GRID_N=240 grid). Clicks on the stage → _svgPoint→_snap. The outline is closed = a click on the first vertex → area select (hass.areas) + name → room {poly}. Polygon rooms and rectangles are rendered uniformly (hit-test: point-in-polygon / rect).

All committed plan-geometry mutations enter one named 50-command Undo/Redo stack. Ctrl+Z, Ctrl+Shift+Z/Ctrl+Y and the toolbar buttons use the same stack; a new mutation after Undo drops the redo branch. The local stack survives the server echo of its own writes, but is cleared when a newer external config revision is adopted. Positional placement is always quantized to the plan grid. Shift may alter a gesture's geometry (square/circle creation, independent resize axes or free rotation), but it cannot create off-grid coordinates.

boundary is one contextual UI tool over the existing open_spans model. Before the first click, independent physical bodies block the room boundary below them; otherwise a dashed span wins over a solid shared boundary, and an outer wall is rejected. A solid shared wall takes two points to open, while a dashed canonical span is restored whole with one click. Interaction widths and junction ambiguity are measured in CSS pixels and converted through the live viewBox, so zoom never changes the effective target. The first point is a transient gesture only: Esc, Undo/Redo, navigation, external config adoption, pointer cancellation and multi-touch discard it without touching history.

Every completed segment of an unfinished room contour is persisted in room_drafts, including the thickness selected when that segment was placed. Switching tools keeps it; the same editing session resumes automatically, and after reload either endpoint can be selected to continue. Closing converts the draft into a room, while the room dialog's secondary action converts its edges to independent partitions. partition creates exactly one wall per gesture; column creates a square object whose size comes from the current Thickness field. Double click edits physical-object properties, pointer drag moves the whole object on the grid, and Delete removes only the selected object. The legacy root space.segments array is still stripped on every save.

While drawing, the length of the current segment follows the cursor (_fmtLen → segmentCm/ formatLength): metres, or feet+inches when hass.config.unit_system is imperial. The scale is per-space cell_cm — cm represented by one grid cell (default 5, so 240 cells ≈ 12 m).

Editor chrome and contextual controls

Every editor uses one stable primary .editbar. Its .editbar-tools contains only persistent tools and Undo/Redo; .editbar-end is a separate pinned end cap for Close. Selection, operation and tool-state changes must not insert controls into this measured row.

Transient UI is resolved into one EditorSecondaryModel and rendered by the single .editor-secondary-host inside .stage. Generic state, group navigation, focus/animation lifecycle, outside-dismiss handling and the stable light-DOM template live in editor-secondary.ts; its CSS is isolated in editor-secondary.styles.ts. The root card only builds Plan/Decor models and supplies typed product callbacks. Keeping the existing light DOM is deliberate: layout selectors, focus queries and browser-smoke hooks remain unchanged.

The host is absolutely positioned, has pointer events only on its visible surface and is outside the header/_hdrH measurement boundary. Plan selection actions, drawing thickness and operation hints, Background selection/style actions and the furniture palette all use this surface. The Device editor uses the same empty host and must route future marker quick actions through it.

Every mutating secondary action captures a deterministic contextId and revalidates it before invocation, so a callback from an old selection cannot modify a newer target. Delete/Backspace do not fall through while focus is inside any secondary surface. The same host also implements an explicit second-level EditorToolbarGroup contract (launcher, one open group, keyboard navigation, focus restoration and outside-dismiss consumption), but no current tools are grouped without a separate product decision. The change is UI-only: plan/config models and geometry commands are unchanged.

Doors, windows & gates (v1.23.0+)

space.openings[] — plan geometry, not markers: an opening needs an angle, a length and a wall, while markers are free points whose positions live in the layout store. Model: {id, type: door|window|gate, x, y, angle, length, contact?, lock?, invert?, flip_h?, flip_v?} (normalized coords; length normalized by plan width). Placement snaps onto the nearest derived wall via snapToWall (logic.ts) — the angle is normalized to [-90, 90) because two rooms share a wall with opposite edge directions, and without that a drag across segment boundaries flips the hinge. The opening then keeps absolute coordinates, so editing, merging or deleting rooms never breaks it.

Rendering (after easy-floorplan, MIT): SVG symbol at the origin (jambs + hinged leaf + a quarter-circle arc revealed via stroke-dashoffset), translated/rotated onto the wall; windows are two casement leaves. A gate has the same data/light/contact/lock semantics as a door, but uses two half-width leaves opening only 10° toward the exterior face and no large swing arc. Its default width in the editor is 300 cm. openingAmount (pure) maps the contact state to 0..1: no sensor → door/gate drawn open / window closed (static-plan convention); unavailable/unknown freeze that default. The lock renders as an HTML padlock badge (.oplock) in the device layer; a lock is never toggled from the plan (TOGGLE_FORBIDDEN_DOMAINS rule). View-mode UX: hover outline, drag along walls (continuous re-snap, saved on release), click → status card (250 ms timer), double click → properties dialog. In markup mode the "Opening" tool handles clicks instead.

For a wall with thickness, one OpeningWallIndex resolves the atomic wall interval and adjacent room on each side of the centreline. Opening symbols, wall cuts and room-coloured tunnel patches all consume this association; none has a separate nearest-wall fallback. A candidate must be genuinely adjacent to the opening axis, so a detached parallel room inside one grid cell cannot own the far half. Full-width coverage, signed inner-face distance, room area and stable room id form the deterministic tie order.

The full card caches that index and the batch tunnel geometry by space, _cfgEpoch and complete room/wall/opening geometry. A normal HA state tick therefore resolves only live room fill values, not roomWallProfile again. The batch helper removes already-painted intervals from later overlapping openings, preventing double alpha. A base patch beneath Glow/sun repeats the same frame-local effective fill as the room shape. Outer openings give the one room both halves; shared openings use a local-coordinate hard stop at y=0. Virtual spans, unfinished drafts and zero-thickness walls are ignored; legacy spans are clipped per atomic body.

Integration WS API

Command	Parameters	Response
houseplan/layout/get	—	{layout: {device_id: {x,y}}, rev}
houseplan/layout/set	layout, expected_rev?	{ok, rev} / err conflict; event houseplan_layout_updated
houseplan/layout/update	device_id, pos	{ok, rev}; event houseplan_layout_updated
houseplan/config/get	—	{config, rev}
houseplan/trail/get	—	{trails: {marker: {current, previous}}} — vacuum runs, raw robot coords
houseplan/trail/delete	marker_id	{ok, removed} — erase current/previous runs after marker deletion
houseplan/config/set	config, expected_rev?	{ok, rev} / err conflict; event houseplan_config_updated
houseplan/plan/optimize	config, layout, both expected revisions	crash-resumable two-store commit + one-deep backup
houseplan/plan/optimize_undo	both expected revisions	restores backup only before any later edit
houseplan/plan/set	space_id, ext (svg/png/jpg/webp), data (b64, ≤8 MB)	{ok, url} — writes <space>.<token>.<ext>, deletes nothing
houseplan/plans/list	—	{plans: [{name, url, size, modified, used_by}], total} (newest 60)
houseplan/plans/delete	name	{ok, removed} / err in_use
houseplan/layout/delete	device_id	{ok, rev}; event houseplan_layout_updated
houseplan/geometry/repair	space_id, aspect, dry_run?, undo?	preview / {ok, rev, moved} / {restored}; errs nothing_to_repair, no_backup
houseplan/files/migrate	from_id, to_id	{mapping} — COPY, never move
houseplan/files/cleanup	marker_id, keep?	replacement-only collection
houseplan/content/sign	paths[]	{urls} — authSig for <image>/<a> fetches

Manual attachments upload over HTTP (streaming, transactional staging), not WS — the old houseplan/file/set was removed in v1.10.0.

If the v1.48 migration crashed halfway (HP-1500-01): the config write landed, the layout write did not, and both triggers are gone — markers of that space sit in the old coordinates and nothing in the data can prove it. The geom_pending intent (v1.50.0) prevents this for any future migration, but cannot help an install that was already stranded. There is no safe automatic answer — re-transforming a layout that is actually correct would corrupt it — so the fix is explicit: houseplan/geometry/repair {space_id, aspect} re-applies the transform to that one space's positions. dry_run: true previews, the previous positions ride the same store write as a one-deep backup, and undo: true restores them. Admin-gated like every other write.

The canvas is square, the image is not (v1.48.0). A space used to carry an aspect, and coordinates were normalised against it — x by the width, y by the height. That made every geometric question depend on a per-space number for no benefit. Now the render space is NORM_W × NORM_W and a plan image is fitted inside it by its own ratio (fitInSquare, shared by both renderers), which is stored as plan_aspect so the layout does not jump before the file loads. Upgrading runs geometry_migration.migrate_config once: it pads the old box out to a square and re-expresses every coordinate against it — a uniform scale plus an offset in render units, so angles and proportions are exact — and scales cell_cm for tall plans, since the grid pitch is a fraction of the width.

User content is served inert (HP-1454-01). An uploaded SVG is the only thing here that a browser will happily treat as a document rather than an image, and it would be a document of Home Assistant's own origin. Inside the card that never matters — <image> does not run scripts — but the url is reachable directly, and uploading needs only write access, which by default every user has. HouseplanContentView therefore sends a sandbox CSP with SVG and only with SVG: a CSP on a PDF response can break the browser's built-in viewer, and a raster image has no execution model to disable.

Attachments follow the same commit-scoped lifecycle as plans (HP-1454-02). An upload takes a free name and never overwrites, because the bytes under an existing name may be referenced by the stored configuration and an upload is not part of that transaction. reserve_filename claims the name as it picks it (O_CREAT | O_EXCL) — asking exists() and returning a string let two uploads agree on one name and quietly overwrite each other. It also budgets the length so the result survives the sanitiser the content view applies to the request, since a name the view rewrites is a file written and never served. Streaming temporaries live in the files root under .upload-, are removed on every exit path of the request (including cancellation, which is a BaseException and slips past except Exception), and are swept at startup and daily. That scheduled pass also runs the two collectors with the stored configuration as both sides — nothing superseded, so every referenced file is kept and only aged unreferenced ones go. Without it, collection would only ever happen when somebody saves, and a file uploaded into a dialog that was then cancelled would wait for a write that may never come. A new icon has no id yet, so its files go to a per-dialog staging folder and move to the real id once the config write is accepted — the same copy → save → cleanup order as a rebind. config/set collects what its commit superseded — that much a commit knows for certain. Unreferenced is a far weaker signal, and the policy follows from one asymmetry: a few unnecessary megabytes can always be removed by hand; a file we should not have removed cannot be brought back. When the evidence is weak, keep the file. Owner's decision, 2026-07-28, after the one-hour rule applied to every unreferenced file destroyed two detached plans.

The classification is by owner, not by "is it referenced". A file leaving the configuration looks identical whether the plan was replaced, detached, or its space deleted — and only the first is a deletion the user asked for. Reading old_refs - new_refs and calling it "superseded" deleted a plan the moment it was detached, under documentation promising the opposite (HP-1465-01).

Case	What it means	Rule
Space in both, plan A → plan B	the user picked another image	removed immediately
Space in both, plan → none	detached; one click undoes it	kept
Space gone	deliberate, but the image was imported and may be nowhere else	kept
Space has a plan, plus another file of its own	an upload whose save was rejected	kept — ageing these out raced the retry that referenced them
Marker in both, attachment dropped from its list	a trash button, promising nothing	removed immediately
Marker gone	same call as a deleted space's plan	kept
Attachment in up_*	a dialog that was never saved; no device owns it	PLAN_ORPHAN_TTL_S (1 h)
Marker there, file it never listed	a rejected upload	kept, same reason

Nothing is deleted for being old, with one exception: a per-dialog staging folder (up_*), which by construction can only hold an upload from a dialog that was never saved. The disk therefore stays bounded by the user, not by a timer — houseplan/plans/list shows every stored plan with its size and which space uses it, and houseplan/plans/delete removes one on request, refusing while a space still references it. That listing is what makes "we never delete" livable: a detached plan is not lost, it is one click away in the space dialog.

Config writes are serialized (HP-1454-03). _writeConfig() chains onto a single promise: one config/set in flight, each carrying the revision the previous one returned. The debounce still spaces out when a write starts; what it cannot do — and used to be relied on for — is keep two writes from overlapping, which produced a self-inflicted conflict and lost the newer edit.

Plan uploads are copy-on-write, and collection belongs to the commit (reviews R2-1, R3-1). The file system is not part of the config's optimistic-locking transaction, so nothing referenced may be overwritten or deleted before the CAS succeeds: the upload writes a new versioned name and removes nothing. Deciding what may then go is not a client's call — a cleanup request cannot be ordered against another client's commit, and a delayed one deletes a plan that was just saved. So config/set collects itself, inside its write lock, from the pair of configurations that bracket the commit (plans.collect_plans): a file the commit REPLACED goes immediately, and nothing else goes at all — see the table above; only a per-dialog staging folder ages out. Growth is bounded at the door instead, by plans.check_quota on every upload (store size, file count, free disk), because a limit that deletes is how plans were lost twice. The . between id and token is load-bearing — a space id cannot contain one, so <space>.<token>.<ext> can never be confused with the files of a space whose name merely starts the same way.

An internal plan url must exist when it is stored (HP-1470-02). The picker can attach a plan and then delete it, and two clients can do the same in either order — the write lock orders the requests but says nothing about whether the file survived. config/set therefore checks every /api/houseplan/content/plans/ url against the disk before saving, and refuses with missing_plan. External and legacy urls are the user's own and are never second-guessed.

Signed content urls are batched, aged and deduplicated (reviews R2-2, R3-2, R4-2). ContentSigner in src/signing.ts is the single implementation, used by both cards; the duplicate inside houseplan-space-card signed correctly and never handed the result to its renderer, which is the failure mode a second copy invites. MAX_SIGN_PATHS (200) is a shared contract between logic.ts and const.py: the backend caps a request there and says nothing about the rest, so the card must chunk. Cached signatures carry the time they were issued — an aging one keeps rendering while its replacement is fetched, an expired one is dropped rather than served (it would 401 and raise a failed-login warning). The cache is pruned to the urls the live config references, so it cannot grow past the cap through history alone. Queued and in-flight are distinct states: a render happening while a request is out must not queue the same url again, a failure backs off rather than retrying on the next frame, and an in-flight entry expires after SIGN_INFLIGHT_MS so a promise that never settles cannot block retries forever.

Room climate is one pass per hass snapshot (review R2-3). areaClimateMap() classifies the whole registry once and returns Map<area, {temp, hum}>; the card memoizes it on hass identity, which Home Assistant replaces on every state change. Per-room lookups are O(1). areaClimate() survives as a single-area wrapper for tests — using it in a render reintroduces the O(rooms × entities) cost it was extracted from.

File uploads go over HTTP (not WS, which has a message-size limit): POST /api/houseplan/upload (multipart: marker_id + file), HomeAssistantView, requires_auth. Served from /houseplan_files/files/.

Second card: houseplan-space-card (read-only, v1.16.0)

The bundle registers two custom elements from one entry (src/houseplan-card.ts imports ./space-card):

• houseplan-card — the full interactive card.
• houseplan-space-card — a static, read-only schematic of ONE space for embedding.

Shared, framework-light modules keep the two views from diverging:

• src/space-geometry.ts — pure model/position math (spaceModels, roomBounds, roomCenter, defaultPositions, markerPos, labelPos; no Lit import) — unit-tested, mirrors the full card's private geometry.
• src/space-render.ts — renderSpaceStatic() draws the plan + configured room borders/names + device markers (via buildDevices, same filtering) with NO marker handlers. Current states, values, alarms, temperature/LQI badges and witnessed activity use the shared ResolvedDevicePresentation and renderDeviceFace; optional card settings can disable ordinary live dressing, temperature or signal without creating another semantic implementation.
• src/config-store.ts — module-level {config, rev, layout} cache shared by all embedded cards (dedupes houseplan/config/get), seeded synchronously from the full card's localStorage snapshot (houseplan_card_cfg_v1) and invalidated on houseplan_config_updated.

Static contract: the schematic layer (.hp-static-stage) is pointer-events:none; the footer button lives outside it and stays clickable.

Deep-link contract: the footer button calls navigate(button_target + "#space=<id>") (default target /plan-doma). The full card reads #space=<id> on load (a valid id wins over default_floor) and on hashchange, without blocking manual space switching; an invalid/absent hash falls back to the default.

Additions v1.28–v1.41 (2026-07-24)

• Decor layer (space.decor[], v1.33; unified editor 2026-08-07): purely visual line/rect/ellipse/text/furniture shapes, normalised geometry and physical per-shape style. src/editors/decor/types.ts is the typed persisted union; geometry.ts owns cm↔render conversion, oriented boxes and the decor+room magnet; hp-color-opacity is the shared colour/alpha control. houseplan-card.ts still owns orchestration, but every kind uses one selection/transform/history pipeline. DECOR_SCHEMA accepts canonical width_cm, text size_cm, opacity/fill fields, optional per-line line_style (solid / dashed; the frontend omits the legacy solid default), and legacy width/text-size representations for read compatibility.
• Plan image transform: planRect() resolves the fitted image plus plan_x/y, independent plan_scale_x/y and plan_angle; legacy plan_scale feeds both axes. The image is interactive only in its own Background tool, rotated corners contribute to content bounds, and the static card uses the same model. See DECOR-EDITOR.md and BACKDROP.md.
• Independent Glow overlay (#55): settings.glow_enabled is orthogonal to the data fill_mode; room settings.glow is the tri-state-compatible model foundation for #36. Legacy fill_mode: 'glow' remains a permanent read token and projects to data fill none plus Glow true unless an explicit boolean wins. Normal settings/room saves materialise that projection in the same write; Optimize Plans performs the equivalent idempotent model-v6 migration. Render order is paper → resolved data room/tunnel fill → conditional pointer-free Glow base for rooms whose resolver result is absent or fully transparent → radial pools → sun/interactive layers. A resolved data/static fill (lqi, light, temp, custom) never receives the dark base, so its exact color and alpha remain visible; a dynamic mode without usable data or a custom fill with zero opacity receives the base instead of exposing bright paper. Radial pools stay independent and continue to render. The static room card uses the same data/base projection, omits empty base groups, and deliberately has no live pools.
• Custom room fill (#56): space.settings.custom_fill is the space color and room.settings.custom_fill is an optional explicit override. The pure projection is room → space → {c:'#607d8b',a:.18} and every read crosses safeStoredColor plus finite alpha clamping. resolveEffectiveRoomFill remains the single source for room floor, clean-floor holes and thick-wall tunnel colors; stored room_color continues to control borders/names only.
• Glow pools and additive composition (#19): every source retains its own radial gradient and wall/door clipPath. All pools live in one flat isolated group with no outer opacity; only the pool elements use SVG mix-blend-mode: screen. resolveGlowAppearance resolves the marker-owned live/manual colour and brightness, while glowAlpha is the only intensity formula: paletteAlpha * .7 * (.4 + .6 * bri^(1/2.2)). The resulting stop alpha is shared by the room pool and doorway spill. A cached per- Document raster probe verifies actual SVG screen pixels rather than trusting CSS syntax support; pending/unsupported/error/timeout states render with deterministic normal blending and a successful probe requests one update. Radius remains global settings.glow_radius_cm with optional per-marker glow_radius_cm. On thick walls the doorway sector uses the near/far clear spans so jamb returns clip the spill as a real opening tunnel. The shared light resolver marks external controls as non-spatial: they vote in room state/statistics and drive group actions but never place a pool at the controller. wall-thickness.ts and the card orchestrator continue to own all geometry/caches; render/opening-tunnels.ts only projects immutable inputs.
• Open boundaries (v1.37, revised 2026-08): space.open_spans hold geometric virtual stretches; room.open_to remains the light-zone index derived from spans (legacy open_to-only configs expand to full sharedBoundary on read). Shared stretches drawn as a TRUE dash; outlines trimmed (outlineWithout/cutSegments). In View the dash group is painted before thick wall bodies, letting real jambs mask its centreline ends; in all editors it is painted after the bodies so saved spans and previews remain fully visible. Geometry mutations clip one stored span to every surviving shared segment. Adjacent pieces owned by different room pairs stay separate: their midpoints are the source of the corresponding open_to links after Split (AUD-159B7-01).
• Marker controls (v1.36): persisted marker.controls[] is a lossless, ordered external-target list. Opening and saving the dialog preserves duplicates and temporarily unknown/vendor targets, removing only the marker's own bound/device entities. The runtime projection separately de-duplicates and filters to currently controllable lights/switches, then toggles them as one HA-group-semantics service call on the marker's explicit tap_action=toggle; icon state/tint mirrors those effective targets.
• Resolved device state (2026-08-06): HA provides states per entity, not one state per device. resolvedDeviceStateEntities therefore starts from uncategorised registry entities, resolves one functional role (whole-device domains, then semantic binary signals, then one representative switch), and aggregates passive readings as the final fallback. _visualSamples consumes the full result; primaryEntity only selects its first member where a single action target is required. Integration option switches can no longer make an otherwise healthy device working or unavailable merely by list order. For A switch-only device never aggregates sibling option switches: integrations which fail to categorise night mode, voice enhancement or child lock cannot paint the whole marker as working. When generic HA metadata identifies a dedicated Power switch in such a composite controller, on is a neutral powered lifecycle and off reuses the faded unavailable presentation; a lone relay keeps normal working-state yellow. For climate, a recognized explicit hvac_action is authoritative: idle remains neutral and heating/cooling/preheating/defrosting are working. Unknown vendor pseudo-actions are ignored; when no recognized action exists, a current non-off state advertised by hvac_modes (or a standard HA HVAC mode) is the best available enabled-mode fallback.
• Resolved light sources (UX-12): resolvedLightSources(hass, devices, room?) is the only light-membership resolver. marker.is_light is a real tri-state: absent/null keeps automatic role discovery, true adds the marker's own controllable source, and false suppresses only that own candidate. External controls[] remain independent room-state votes; selectSpatialGlowSource filters them before choosing the first on (or first available) physical source. The resolver excludes hidden markers, de-duplicates entity ids, and honours marker.room_id before an HA area. Glow, Light fill, room light stats, marker indication/card ordering and group toggle all consume this result instead of maintaining separate domain tests. Per-marker glow_color:{c,bri?} can override colour alone or colour plus brightness; strict invalid overrides fall back atomically to live source values.
• Island rooms (v1.34): full nesting is legal (polyContainsPoly); parents render as evenodd paths with holes (islandsOf).
• Kiosk mode (v1.41): a card-config flag, not a mode — _setMode is hard-blocked, header hidden, swipe/carousel handled in the stage pointer pipeline (swipeTarget), per-screen multipliers in LS_KIOSK.
• Nav persistence (v1.38.2): LS_NAV stores {space, mode}; hash deep-link > saved > default_floor; stale-cache retry after the live load.

Settings tiers (owner's principle, 2026-07-26)

Four levels: global (config.settings) → space (space.settings) → room (room.settings) → device (marker.*). Duplicated options are deliberate: the more specific tier overrides the more general one; "unset" always means "inherit". Resolution lives in pure helpers (spaceDisplayOf, roomFillModeOf, sourceValue, resolveTapAction) — never inline in render. The UI will later be unified around this model; until then each tier keeps its own dialog (general settings gear / space gear / room-card gear / marker dialog).

Audit follow-ups (2026-07-27)

• Content is authenticated. /houseplan_files/… now serves ONLY the card bundle (a Lovelace resource must be public). Plans and marker files go through HouseplanContentView (/api/houseplan/content/<plans|files>/…, requires_auth). contentUrl() rewrites legacy stored URLs on read, so no storage migration is needed. Static paths cannot be unregistered — the old routes survive until the next HA restart.
• Optimistic UI, stated explicitly (audit L7). _serverCfg is mutated in place before a fallible save in ~22 places and there is no rollback: after a rejected save the UI shows the edit until the next reload. This is a deliberate optimistic-UI choice, not drift. Paths where it is unacceptable need their own rollback.
• Split invariant. splitRoomPath guarantees a partition: the two parts' areas sum to the original (within epsilon) or the cut is rejected.