BG: drawn-plan paper follows the room contours, not their bounding box

Owner: the white backing must hug the ROOMS — an L-shaped house or detached
buildings grew a white square around the plan. Drawn plans now paper one
opaque shape per room (paperRoomShapes in logic.ts) in exactly the room's own
geometry — polygon points / rounded rect verbatim — so the union of the stack
is the paper: islands paint over their parent, open (virtual) boundaries
change nothing, and the scene bg_color / daynight sky reaches the exterior
walls, shows in the L's pocket and between buildings. Image plans keep the
backdrop-image rect (the canvas IS the paper). A live resize preview
(_rszPreview) feeds _renderCfg, so the paper moves WITH a dragged wall.
Static space-card follows the same contract. Paper is fill-only (stroke:none).

smoke_bg_color §11–13 rewritten: L-shaped + detached test rooms, paper-per-
room DOM checks, resize-preview wiring, pixel probes (acid in the pocket and
between buildings, none inside rooms); §13 injects the snapshot directly —
the module-level config-store cache made the old WS mock a no-op. Was 8 red
on the previous build, green now. docs/SUN.md + docs/TESTING.md contract
updated; unit test for paperRoomShapes.

docs/SUN.md

@@ -63,15 +63,20 @@ only — no entities are created, no services are called.
   without `sun.sun`) it behaves as `'static'`.
 - **The scene background never bleeds through the plan** (owner,
   2026-08-03). In BOTH modes the background — `bg_color` or the
-  daynight sky — is visible only AROUND the plan: an opaque
-  `rect.hp-paper` sits under everything the plan draws and hugs the
-  plan's extents (the backdrop image rect, or the drawn content bounds
-  the opening view fits). Its colour is the pre-bg_color canvas —
-  white for hand-drawn plans, the theme card background under an
-  image. The night dimming above is the `brightness` filter on the
-  zoomwrap ONLY; the paper's alpha never changes. Applies to
-  view/kiosk/editors and the static space-card alike
-  (smoke_bg_color).
+  daynight sky — is visible only AROUND the plan: opaque `.hp-paper`
+  shapes sit under everything the plan draws. An image plan papers the
+  backdrop image rect (the canvas IS the paper); a hand-drawn plan
+  papers the ROOM CONTOURS — one shape per room in exactly the room's
+  own geometry (fill only, no stroke), never their bounding box, so
+  the background reaches the exterior walls of an L-shaped house and
+  fills the gaps between detached buildings (an empty drawn space has
+  no paper). Open (virtual) boundaries do not affect the paper; a live
+  resize preview moves it together with the rooms. Its colour is the
+  pre-bg_color canvas — white for hand-drawn plans, the theme card
+  background under an image. The night dimming above is the
+  `brightness` filter on the zoomwrap ONLY; the paper's alpha never
+  changes. Applies to view/kiosk/editors and the static space-card
+  alike (smoke_bg_color).
 
 ## Window light wedges — `settings.sun_rays`
 

docs/TESTING.md

@@ -882,13 +882,18 @@ require hands on real hardware — they remain for the human pass.
 - [ ] Opaque plan paper (2026-08-03, owner): the scene background —
       `bg_color` or the daynight sky — is visible ONLY around the plan and
       NEVER bleeds through it, in view/kiosk/editors and on the static
-      space-card. An opaque `rect.hp-paper` under everything the plan draws
-      hugs the plan's extents (the backdrop image rect, or the drawn
-      content bounds the opening view fits); a hand-drawn plan keeps its
-      historical white canvas, an image plan the theme card background.
-      At night (`daynight`) the paper dims via the zoomwrap `brightness`
-      filter only — its alpha stays 1. Pixel-proofed against an acid
-      `#ff00ff` background [auto: smoke_bg_color]
+      space-card. An image plan papers the backdrop image rect
+      (`rect.hp-paper`). A hand-drawn plan papers the ROOM CONTOURS: one
+      `.hp-paper` shape per room in exactly the room's own geometry (fill
+      only, no stroke), so an L-shaped house or detached buildings never
+      grow a white bounding rectangle — the scene colour reaches the
+      exterior walls, shows in the L's pocket and between buildings, and an
+      empty drawn space has no paper at all. A live resize preview
+      (`_rszPreview`) moves the paper together with the dragged wall.
+      Colours: historical white for drawn plans, the theme card background
+      under an image. At night (`daynight`) the paper dims via the zoomwrap
+      `brightness` filter only — its alpha stays 1. Pixel-proofed against
+      an acid `#ff00ff` background [auto: smoke_bg_color]
 - [ ] Per-space overrides (background mode, north, sun-in-windows) inherit
       when empty, exactly like show_lqi/fill_mode
 - [ ] «Sunlight through windows» (default OFF): wedges appear only from