feat v1.23.1: openings — hover outline, drag along walls, double-click properties

- Hover: an accent outline hugs the opening's wall strip + grab cursor.
- Drag (view mode): re-snaps continuously to the nearest derived wall; snapToWall now
  normalizes the angle to [-90,90) — neighbouring rooms yield the same wall in opposite
  directions, which used to flip the hinge while dragging across segment boundaries.
  setPointerCapture wrapped in try/catch (an inactive pointerId must not kill the drag).
- Click still opens the status card (via a 250ms timer); double click opens the
  properties dialog from view mode. Hit zone is now a slightly thicker strip along the
  wall instead of the whole swing square (fewer accidental hovers). +1 test (77).
Verified live: drag moved a test door exactly along a vertical wall (angle 90 -> -90),
click/dblclick/markup-tool paths all работают; the user's 12 real openings untouched.

custom_components/houseplan/manifest.json

@@ -16,5 +16,5 @@
   "issue_tracker": "https://github.com/Matysh/houseplan-card/issues",
   "requirements": [],
   "single_config_entry": true,
-  "version": "1.23.0"
+  "version": "1.23.1"
 }