v1.49.0: content-fit zoom, swipe animation, wording, and the v1.47.0 review

Owner's batch:
- zoom now opens on what is DRAWN (rooms + 5% margin) for spaces with no
  background image; with one the image is the plan and still fits whole. A small
  plan on the square canvas no longer opens as a speck.
- swiping between spaces, and the kiosk carousel, slide sideways; honours
  prefers-reduced-motion.
- the room settings button reads 'Room settings' and lightens on hover.
- 'curation' is filtering everywhere: UI strings, docs, code.

Checked the yard while I was there: its drawing sits off-centre because it was
drawn that way — before the migration x spanned 0.12..0.54 with 0.12 and 0.46 of
margin. The migration added 0.1465 on each side, symmetrically. Content-fit zoom
makes it moot anyway.

From the v1.47.0 review:
- HP-1470-02: the picker let you delete the plan you had just selected — it is
  not in the stored config yet, so the server rightly called it free, and the
  save then stored a url with no file. The button is disabled, and since two
  clients can do this in either order, config/set now verifies every internal
  plan url against the disk under the write lock and answers .
  External and legacy urls are not ours to police.
- HP-1470-01: growth is bounded at the door rather than by deleting old files —
  that mistake cost real plans twice. check_quota refuses an upload that would
  push the store past 256 MB / 200 plans (1 GB / 1000 attachments) or leave less
  than 512 MB free. The plan list is capped at 60 newest with a total, and
  thumbnails load lazily.
- HP-1470-03: picking a saved plan waited for nothing and stored a fallback
  ratio when the signature had not arrived — a square plan came out stretched.
  It waits for the signature, binds the result to the dialog that asked, and the
  dialog preview is signed too.
- report §5: the last lifecycle comments still described age-based collection.

Not released yet — the owner asked for a release once the batch is done.

test/space-geometry.test.mjs

@@ -1,7 +1,7 @@
 import test from 'node:test';
 import assert from 'node:assert/strict';
 import {
-  NORM_W, spaceModels, roomBounds, roomCenter, defaultPositions, markerPos, labelPos, fitInSquare,
+  NORM_W, spaceModels, roomBounds, roomCenter, defaultPositions, markerPos, labelPos, fitInSquare, contentBounds,
 } from '../test-build/space-geometry.js';
 
 const cfg = {
@@ -83,3 +83,26 @@ test('defaultPositions: several devices in one room are spread (declumped, disti
 });
 
 test('NORM_W is 1000', () => assert.equal(NORM_W, 1000));
+
+test('contentBounds: fits what is drawn, with a 5% margin', () => {
+  const one = spaceModels({ spaces: [{
+    id: 's', view_box: [0, 0, 1, 1],
+    rooms: [{ id: 'r', poly: [[0.4, 0.4], [0.6, 0.4], [0.6, 0.6], [0.4, 0.6]] }],
+  }], markers: [] })[0];
+  // 200x200 render units in the middle of a 1000x1000 canvas, +5% of 200 each side
+  assert.deepEqual(contentBounds(one), { x: 390, y: 390, w: 220, h: 220 });
+
+  // rectangles count too, and the margin follows the LARGER side
+  const rect = spaceModels({ spaces: [{
+    id: 's', view_box: [0, 0, 1, 1],
+    rooms: [{ id: 'r', x: 0.1, y: 0.4, w: 0.6, h: 0.1 }],
+  }], markers: [] })[0];
+  const b = contentBounds(rect);
+  assert.equal(Math.round(b.w), 660);   // 600 + 2 * 5% of 600
+  assert.equal(Math.round(b.h), 160);   // 100 + the same absolute margin
+  assert.equal(Math.round(b.x), 70);
+
+  // nothing drawn → the caller keeps the whole canvas
+  const empty = spaceModels({ spaces: [{ id: 's', view_box: [0, 0, 1, 1], rooms: [] }], markers: [] })[0];
+  assert.equal(contentBounds(empty), null);
+});