v1.45.3: 'value instead of an icon' could never be saved (issue #3)

The device editor has offered display='value' since v1.26.0; MARKER_SCHEMA
accepted only badge/ripple/icon_ripple. Picking it produced

  not a valid value for dictionary value @ data['config']['markers'][n]['display']

and since one rejected marker fails the whole config write, the user could not
save the plan at all until the setting was undone. Reported by @RemyRoux with
the exact error text, 2026-07-27 — a year and a half after the feature shipped.

The schema now accepts it, and the class of bug is closed rather than the
instance: DISPLAY_MODES, TAP_ACTIONS, SPACE_FILL_MODES and ROOM_FILL_MODES are
exported from src/logic.ts, the editors render their options from them, and a
backend test parses those lists out of the TypeScript source and asserts the
schema accepts every one (and rejects a bogus value). Reverting the one-word
schema fix fails that test, which is the check that was missing.

Plus an HA-harness test saving a config that contains a value-display marker —
the exact call the user's card was making.
Docs: CHANGELOG.md + CHANGELOG.ru.md + TESTING.md + STATUS.md.

docs/TESTING.md

@@ -234,6 +234,11 @@ Run the *core flows* (marked ★ below) in each environment at least once per mi
       are only reachable through /api/houseplan/content/… with a session; the
       old /houseplan_files/plans|files paths return 404 after a restart; old
       stored URLs keep working (rewritten on read) [auto+manual]
+- [ ] Every editor option is storable (v1.45.3, issue #3): set a sensor to
+      "value instead of an icon" and save — no validation error, the value shows
+      on the plan after a reload. Same for each tap action and each fill mode
+      [auto: backend test_every_display_mode_the_editor_offers_is_accepted and
+      neighbours, test_a_marker_showing_its_value_can_be_saved]
 - [ ] Signing does not amplify on a bad connection (v1.45.2, review R4-2): with
       the WebSocket slow or refusing, the card issues ONE sign request per url
       and backs off after a failure instead of asking again on every render; a