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.

docs/CHANGELOG.md

@@ -1,5 +1,36 @@
 # Changelog
 
+## v1.50.1 — 2026-07-29
+
+**From the v1.50.0 review**
+
+- **A card below other dashboard content gets its stage back (HP-1500-02).**
+  The v1.50.0 height measurement used the absolute document coordinate, so a
+  tall card before this one was billed as "header" and the stage collapsed to
+  zero. The card now measures only its own chrome plus a bounded allowance for
+  what the dashboard keeps above it, and re-measures on window resize; the
+  listener is removed on teardown.
+- **The content frame can no longer be degenerate or absurd (HP-1500-03).**
+  A lone marker in an empty space produced a zero-area viewBox — a blank
+  scene; a single stored coordinate like 1e100 (any finite float passed
+  validation) stretched the frame until the plan was a dot, for every viewer
+  of the space. A near-zero axis now opens up to a floor of canvas around the
+  marker, points far outside the canvas envelope no longer command the frame
+  (they still render where they are), and the server refuses layout
+  coordinates outside ±4 — generous slack for an icon dragged past an edge,
+  not an envelope for absurdity. A real thin room keeps its tight frame, and
+  the gate sensor slightly past the edge still counts.
+- **A repair path for installs stranded by the v1.48 migration window
+  (HP-1500-01).** If the old migration crashed between its two writes, the
+  markers of a space are left in the old coordinates with nothing in the data
+  able to prove it — and re-transforming a correct layout would corrupt it, so
+  nothing automatic is safe. `houseplan/geometry/repair {space_id, aspect}` is
+  the explicit answer: `dry_run` previews the exact moves, the previous
+  positions ride the same store write as a one-deep backup, `undo` restores
+  them, and routine drags no longer erase that backup. The v1.50.0
+  `geom_pending` protocol already protects every future migration; this covers
+  the installs it was too late for.
+
 ## v1.50.0 — 2026-07-28
 
 **Owner's batch**