v1.46.0: full external audit of v1.45.4 — HP-1454-01 … -10

HP-1454-01 (high, release blocker): an uploaded SVG plan opened directly is a
top-level document of Home Assistant's own origin, so a <script> inside it
reaches the session's localStorage and API. Uploading needs write access, which
by default every authenticated user has. SVG responses now carry a sandbox CSP;
only SVG, because a CSP on a PDF can break the browser's viewer and a raster
image has nothing to disable. Verified in Chromium both ways: the script runs
without the header and does not with it.

HP-1454-02: attachment uploads wrote straight to <marker>/<filename>, outside
the config transaction — a cancelled dialog or a rejected save left the stored
url serving new bytes, and every new icon shared one 'new' folder, so two of
them attaching manual.pdf pointed at one file. Uploads take a free name, a new
icon gets a per-dialog staging folder promoted on an accepted save, and
config/set collects superseded and aged-orphan attachments like it does plans.

HP-1454-03: the debounce spaced out the starts of a write, not the writes. A
save slower than 500 ms let the next edit go out with the same expected_rev;
the server accepted the first, rejected the second, and the conflict handler
reloaded over the local copy. Writes are chained now — one in flight, each with
the revision the previous returned.

HP-1454-04: _openPairsCache keyed on room ids and links only, so an aspect
change or a dragged vertex left open boundaries and their glow cuts at old
coordinates. It keys on the rendered model object now — the same invalidation
the model cache already has, not a second strategy. The fingerprint also gained
an O(1) geometry roll-up per room.

HP-1454-05: outer collections were capped, inner ones were not. Limits for
poly points, open_to, controls, pdfs, text and url lengths, plus a total
serialized size cap; legacy  is dropped server-side.

HP-1454-06: upload streams to a temp file and downloads use FileResponse, so a
50 MB manual no longer costs ~100 MB of RSS per transfer.

HP-1454-07: spaceModels() dropped room.settings, so the static card ignored the
per-room fill override. HP-1454-08: layout had no revision on point-wise writes
and no event, leaving static cards stale forever; it now keeps a revision,
returns it and fires houseplan_layout_updated. HP-1454-09: repair cleanup only
walked existing spaces, so a deleted space kept its warning. HP-1454-10:
serialize-javascript pinned past two advisories.

Tests: smoke_svg_sandbox (proves both directions), smoke_config_writer and
smoke_render_parity (both verified failing against a v1.45.4 build), six pure
tests for attachment collection and inner limits, four HA-harness tests for the
CSP, non-overwriting uploads, the size cap and layout revisions.
Docs: CHANGELOG.md + CHANGELOG.ru.md + ARCHITECTURE.md + TESTING.md + STATUS.md.

docs/TESTING.md

@@ -239,6 +239,39 @@ Run the *core flows* (marked ★ below) in each environment at least once per mi
       on the plan after a reload. Same for each tap action and each fill mode
       [auto: backend test_every_display_mode_the_editor_offers_is_accepted and
       neighbours, test_a_marker_showing_its_value_can_be_saved]
+- [ ] Uploaded SVG is inert as a document (v1.46.0, HP-1454-01): open a plan's
+      signed url directly in a tab — a `<script>` inside it must not run and must
+      not reach the HA session's localStorage; the same plan still renders in the
+      card. PDFs still open in the browser viewer
+      [auto: smoke_svg_sandbox + backend test_uploaded_svg_is_sandboxed_and_a_pdf_is_not]
+- [ ] An attachment never overwrites another (v1.46.0, HP-1454-02): attach a file,
+      cancel the dialog — the previously stored file is byte-identical. Attach
+      `manual.pdf` to two NEW icons — two independent files. A cancelled upload is
+      gone an hour later
+      [auto: backend test_upload_never_overwrites_an_existing_attachment + unit: collect_attachments]
+- [ ] Two quick edits both survive (v1.46.0, HP-1454-03): with a slow connection,
+      make an edit and another one before the first save answers — both are in the
+      stored config, only one write is ever in flight, and no conflict toast fires
+      [auto: smoke_config_writer]
+- [ ] Open boundaries follow geometry (v1.46.0, HP-1454-04): change a space's
+      aspect or drag a room vertex — the open boundary and the light through it
+      move with the walls, without a reload [auto: smoke via model-identity key]
+- [ ] Inner limits (v1.46.0, HP-1454-05): max and max+1 for polygon points,
+      open_to, controls, pdfs, text and url lengths; an oversized config as a
+      whole is refused with `too_large`
+      [auto: unit: test_inner_collection_limits + backend test_config_write_is_capped_by_total_size]
+- [ ] Big files stream (v1.46.0, HP-1454-06): upload a ~50 MB manual and download
+      it twice in parallel — HA's memory does not grow by a file per transfer
+      [manual]
+- [ ] Static card parity (v1.46.0, HP-1454-07): a room whose fill is set to "none"
+      under a space filled by light is transparent on BOTH cards
+      [auto: smoke_render_parity]
+- [ ] Layout reaches the static card (v1.46.0, HP-1454-08): drag an icon on the
+      full card — a static card on the same dashboard moves it too, with no
+      config write and no reload
+      [auto: backend test_layout_keeps_its_revision_and_announces_changes + manual]
+- [ ] Repair issues are not immortal (v1.46.0, HP-1454-09): create a missing-plan
+      warning, then delete the space — the warning disappears [manual]
 - [ ] A path the backend cannot sign does not become a request loop (v1.45.4,
       review R5-1): when `content/sign` answers successfully but omits a path,
       the card backs that path off individually and keeps the urls it did get;