v1.50.0: the v1.49.0 review (HP-1490-01..04) and the owner's zoom batch

Owner's batch (committed to dev earlier today, released here):
- devices count as content for the default zoom;
- the editor no longer shifts the plan — the stage measures its own top
  instead of assuming 118px of header;
- zoom goes out to 0.4x, centred.

From the review:
- HP-1490-01: the square-canvas migration wrote two stores in sequence, and
  the first write deleted the aspects the second needed — a crash between
  them stranded the layout in the old coordinates with nothing able to
  finish it. The intent {space: old aspect} is durable now: saved to the
  layout store before anything moves, cleared by the same write that stores
  the migrated layout, each half idempotent behind its own trigger. The
  update event fires only after both halves are on disk. Proven at the exact
  crash boundary by a harness test that fails the layout write once.
- HP-1490-02: check_quota and the file write were two executor jobs with
  nothing between them, so N parallel uploads all measured the store before
  any of them wrote. One job under a dedicated upload_lock now — narrower
  than write_lock on purpose, a directory scan must not stall config saves.
  A failed write reserves nothing.
- HP-1490-03: the content frame fed pan, zoom, clamp AND pointer maths, so
  the editors were boxed into yesterday's drawing. Edit modes measure from
  the full square; mode switches refit rather than carry a view clamped
  against the wrong base.
- HP-1490-04: Save could outrun the proportions read and ship the previous
  file's ratio. Picking a plan clears it immediately; Save awaits the
  bounded read and stores 'unknown' over a lie.
- §5: package-lock version synced, duplicated comment removed.

New: smoke_audit_1490.mjs, migration crash-recovery pure + harness tests,
parallel-quota harness test. Inventory: 138 unit / 49 pure / 40 harness / 64
smokes.

custom_components/houseplan/__init__.py

@@ -20,7 +20,7 @@ from .const import (
     PLANS_URL,
     VERSION,
 )
-from .geometry_migration import migrate_config
+from .geometry_migration import migrate_config, migrate_layout, pending_from_config
 from .plans import collect_attachments, collect_plans, sweep_upload_temps
 from .repairs import async_check_plan_files
 from .store import HouseplanConfigEntry, create_data
@@ -104,20 +104,40 @@ async def async_setup_entry(hass: HomeAssistant, entry: HouseplanConfigEntry) ->
     # normalised against a per-space aspect ratio; the canvas is now always
     # square and a plan is centred inside it. Nothing about the drawing changes
     # — the box is padded and the numbers re-expressed against it.
+    # The two stores are written independently, and the lock is no transaction:
+    # a crash between the writes used to leave the config in square coordinates
+    # with the layout still in the old ones — permanently, because the config
+    # write had already deleted the `aspect` fields the layout half needed
+    # (HP-1490-01). So the intent is made durable FIRST, in the layout store,
+    # and each half carries its own trigger with its own write: the config half
+    # removes `aspect`, the layout half removes the saved intent. Whatever
+    # half is missing after a crash, the next start finishes exactly it.
     async with data.write_lock:
         stored = await data.config_store.async_load() or {}
         cfg = stored.get("config")
         lay_stored = await data.store.async_load() or {}
         layout = lay_stored.get("layout") or {}
-        if cfg and migrate_config(cfg, layout):
-            rev = int(stored.get("rev", 0)) + 1
-            await data.config_store.async_save({"config": cfg, "rev": rev})
-            await data.store.async_save(
-                {"layout": layout, "rev": int(lay_stored.get("rev", 0)) + 1}
-            )
+        pending = {
+            str(k): v for k, v in (lay_stored.get("geom_pending") or {}).items()
+        }
+        merged = {**pending, **pending_from_config(cfg)}
+        if merged:
+            lay_rev = int(lay_stored.get("rev", 0))
+            if merged != pending:  # 1. the durable intent, before anything moves
+                await data.store.async_save(
+                    {"layout": layout, "rev": lay_rev, "geom_pending": merged}
+                )
+            rev = int(stored.get("rev", 0))
+            if cfg and migrate_config(cfg):  # 2. the config half
+                rev += 1
+                await data.config_store.async_save({"config": cfg, "rev": rev})
+            migrate_layout(layout, merged)  # 3. the layout half + intent cleared
+            await data.store.async_save({"layout": layout, "rev": lay_rev + 1})
             _LOGGER.info(
-                "House Plan: migrated %s space(s) to the square canvas", len(cfg.get("spaces") or [])
+                "House Plan: migrated %s space(s) to the square canvas", len(merged)
             )
+            # only once both halves are durable — a client refetching on this
+            # event must never see one migrated half and one old one
             hass.bus.async_fire("houseplan_config_updated", {"rev": rev})
 
     await async_check_plan_files(hass, entry)