v1.48.0: the canvas is always square, the plan is centred inside it

A space carried an aspect ratio, and coordinates were normalised against it: x
by the width, y by the height. Every geometric question therefore depended on a
per-space number, and picking a canvas orientation was a decision the user had
no reason to make. The render space is now NORM_W x NORM_W and a plan image is
fitted into it by its OWN ratio, centred — wide plans get margins above and
below, tall ones at the sides.

Migration (geometry_migration.py, pure and unit-tested) runs once at setup under
the write lock. Nothing about a drawing changes: the old box is padded out to a
square and every coordinate re-expressed against it — rooms as rects and
polygons, openings and their lengths, decor, view_box, and the marker positions
in the separate layout store. In render units it is a uniform scale plus an
offset, so angles and proportions are exact. cell_cm is scaled for tall plans,
because the grid pitch is a fraction of the width: without it a wall would
measure less than it does.

 is now dropped by the schema rather than accepted — a stale tab sending
it would be sending coordinates from the old normalisation too, and honouring
the field would not make them right.

The demo fixture was migrated with the same transform, so the smokes exercise
the new geometry rather than a square-native fake; six of them needed their
render-space helpers updated and one its click coordinates.

Not released — dev only, per the owner's instruction.

docs/STATUS.md

@@ -15,12 +15,12 @@
 
 | Item | State |
 |---|---|
-| Version | **v1.47.0** everywhere (manifest, const.py, package.json, CARD_VERSION); deployed to the home instance |
+| Version | **v1.48.0** everywhere (manifest, const.py, package.json, CARD_VERSION); deployed to the home instance |
 | Workflow | Since 2026-07-22: minor changes go to branch **`dev`** (build + smokes → deploy home → commit → push, NO release); releases are batched on the owner's command (merge dev→main, one tag, one release with a summary changelog, CI checked on dev beforehand) |
 | GitHub | https://github.com/Matysh/houseplan-card — **`main` carries every published release, the latest tag is the current version above**; `dev` is where work lands and is merged into `main` at release time (so `dev` is normally equal to or ahead of `main`, never behind). Push via SSH key `ha_jb` (remote git@github.com:…); API releases via the fine-grained PAT in `~/.git-credentials` (Contents R/W, issued 2026-07-23) |
 | CI | validate.yml (hacs + hassfest + frontend + backend) green; release.yml attaches the bundle on release publish |
 | HACS | Custom repository works. **Inclusion PR: hacs/default#9004** — open, valid, labeled; ~864 older open PRs but merge rate ≈180/mo; realistic ETA 1–3 months (checked 2026-07-24) |
-| Home instance | ha.jbstudio.pro (SSH port 323, key `ha_jb`), deployed **v1.47.0** via direct copy (HACS custom repo also installed) |
+| Home instance | ha.jbstudio.pro (SSH port 323, key `ha_jb`), deployed **v1.48.0** via direct copy (HACS custom repo also installed) |
 | Localization | UI en/ru (src/i18n/*.json), everything user-visible localized incl. kiosk popover |
 | Tests | Four layers: frontend unit (`npm test`, node:test over `test-build/`), pure backend (`pytest tests_backend`, runs anywhere), HA-harness backend (same folder, CI only — needs py3.13 + pytest-homeassistant-custom-component), and browser smokes (`demo/smoke_*.mjs`, headless chromium). **Counts are not written down here** — they went stale within two releases while the version line beside them was kept current, which reads as less coverage than exists (review R5-2). Run `npm run inventory` for the current numbers, or read them off the last CI run |
 | Community | **Telegram chat: https://t.me/ha_houseplan** (created 2026-07-27) — the primary user-facing support channel; GitHub issues stay for bugs/features. Link it from any new release notes and posts |