v1.50.1: the v1.50.0 review (HP-1500-01..03)

- HP-1500-02: the stage budget was the absolute document coordinate, so any
  tall dashboard content before the card was billed as header and the stage
  collapsed to 0px. Measure our own chrome relative to the card plus a
  bounded (<=120px) allowance for what the viewport keeps above us; re-measure
  on window resize, remove the listener in disconnectedCallback.
- HP-1500-03, both layers: contentBounds opens a near-zero axis (< ~an icon)
  up to a 200-unit floor and ignores extra points outside a canvas envelope
  (-25%..125%) for FRAMING purposes only; the server bounds layout coordinates
  to +-4 — any finite float used to pass, and one 1e100 hid the plan from
  every viewer. A thin real room keeps its tight frame; the gate sensor past
  the edge still stretches it.
- HP-1500-01: no automatic double-transform — a correct layout and a stranded
  one are indistinguishable, and guessing wrong corrupts good data. Explicit
  admin command houseplan/geometry/repair: dry_run previews, the backup rides
  the same store write, undo restores, and routine layout writes now preserve
  unrelated store keys instead of eating the backup.

Tests: contentBounds guards (unit), layout coordinate bounds + repair
lifecycle (harness), card-below-content smoke. Inventory: 139 / 49 / 42 / 64.

test/space-geometry.test.mjs

@@ -123,3 +123,25 @@ test('contentBounds: devices outside every room stretch the frame', () => {
   // and junk coordinates are ignored, not spread across the canvas
   assert.deepEqual(contentBounds(one, 0.05, [[NaN, 5]]), contentBounds(one));
 });
+
+test('contentBounds: never degenerate, never unbounded (HP-1500-03)', () => {
+  const empty = spaceModels({ spaces: [{ id: 's', view_box: [0, 0, 1, 1], rooms: [] }], markers: [] })[0];
+  // a single marker has no area — the frame gets a floor instead of a 0x0 viewBox
+  const one = contentBounds(empty, 0.05, [[500, 500]]);
+  assert.ok(one.w >= 200 && one.h >= 200, 'a lone marker still frames some canvas');
+  assert.ok(Math.abs(one.x + one.w / 2 - 500) < 1, 'centred on the marker');
+  // a collinear row: the flat axis gets the floor, the long one keeps its span
+  const row = contentBounds(empty, 0.05, [[100, 500], [900, 500]]);
+  assert.ok(row.h >= 200, 'the flat axis is opened up');
+  assert.ok(row.w > 800, 'the long axis is untouched');
+  // an absurd stored coordinate does not command the frame...
+  const room = 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];
+  assert.deepEqual(contentBounds(room, 0.05, [[1e100, 500]]), contentBounds(room));
+  assert.deepEqual(contentBounds(room, 0.05, [[-1e100, -1e100]]), contentBounds(room));
+  // ...but a device a bit past the canvas edge still counts (the gate sensor)
+  const near = contentBounds(room, 0.05, [[1100, 500]]);
+  assert.ok(near.x + near.w > 1050, 'slightly outside the canvas still stretches the frame');
+});