feat(ui): render the status chips and their split-flap labels from a store

ShellFeedback publishes the loading status and the road network chip, and
CctvControls the camera grid chip, to the gev-status store; the scene
chrome renders them. SplitFlapText plays the departure-board cascade that
splitFlap.js plans, writing only the label's one text node, and rests when
its owner is destroyed. setSplitFlapText and disposeSplitFlap are gone.

docs/CURRENT-STATE.md

@@ -5551,10 +5551,10 @@ pins and share links already supply complete boxes.
 
 ### Split-flap status chips (August 2026)
 
-- The three status chips flip their LABELS over character by character when the text changes, like a departure board: `#global-loading-label` ("LOADING LIVE DATA" → "LOAD COMPLETE"), `#traffic-sync-label`, and `#cctv-sync-label` ("loading frames" → "camera grid ready"). All three route through `setSplitFlapText()` in `src/splitFlap.js`; there is no other writer of those three elements. The progress counters (`#*-sync-progress`, `#global-loading-detail`) are deliberately left as plain `textContent` — they tick several times a second, and flapping them reads as a slot machine.
-- `#global-loading-label` doubles as the universal top-center status banner, so anything routed through `_showGlobalStatusNotice()` flaps as well — in particular the share-link restore notices, of which "Shared military flight could not be restored — feed unavailable" is the longest at 63 characters. That needs no special case: `planSplitFlap()` compresses the stagger to hold the 620 ms budget (26 ms → 6.9 ms per column at that length), every column is reserved for the whole cascade, and `element.textContent` is the complete notice at every instant, so the `aria-live` region announces the whole sentence rather than a fragment. A notice deferred minutes past boot is equally safe: `ensureHost()` re-validates the shell on every call, and the long-lived `Text` node is never replaced.
-- **DOM text is the truth, and its node NEVER moves — do not "fix" this.** The first call upgrades a chip label into a permanent shell (`ensureHost`): a `.gev-flap-text` span holding one long-lived `Text` node, plus an `aria-hidden` `.gev-flap-cells` sibling. After that the ONLY text operation for the life of the chip is `node.data = next`. Nothing is reparented, so the label is never transiently empty and the `aria-live` region never sees a removal/reinsertion pair it could announce twice. `element.textContent` is the settled string at every instant, because the cells carry no text at all: both glyphs are CSS generated content (`::before` from `data-flap-prev` = outgoing, `::after` from `data-flap-next` = incoming), which never reaches `textContent`. This keeps QA pins honest and lets `_updateTrafficSyncChip`'s own `textContent !==` guard keep working. The shell is built on a tick where the text is NOT changing, so no real label change ever carries a structural mutation.
-- **No animation loop, and exactly ONE `setTimeout` per change.** CSS `animation`/`transition` only, triggered once per text change and staggered through a per-cell `--gev-flap-delay`. The single timer is the settle that strips the cells; the width ease ends on a `transitionend`/`transitioncancel` listener, never a second timer. Idle cost is zero, there is no periodic work, and nothing requests a Cesium render or takes a render-governor hold. `setSplitFlapText` is a no-op on unchanged text, which is required — the chips are repainted by a 60 ms and a 500 ms ticker.
+- The three status chips flip their LABELS over character by character when the text changes, like a departure board: `#global-loading-label` ("LOADING LIVE DATA" → "LOAD COMPLETE"), `#traffic-sync-label`, and `#cctv-sync-label` ("loading frames" → "camera grid ready"). ShellFeedback and CctvControls publish them to the `gev-status` store, and the scene chrome renders each label with `SplitFlapText.vue`, which plays the cascade `src/splitFlap.js` plans; there is no other writer of those three labels. When an owner is destroyed it publishes the label `stopped`, which rests it at once. The progress counters (`#*-sync-progress`, `#global-loading-detail`) are deliberately left as plain `textContent` — they tick several times a second, and flapping them reads as a slot machine.
+- `#global-loading-label` doubles as the universal top-center status banner, so anything routed through `_showGlobalStatusNotice()` flaps as well — in particular the share-link restore notices, of which "Shared military flight could not be restored — feed unavailable" is the longest at 63 characters. That needs no special case: `planSplitFlap()` compresses the stagger to hold the 620 ms budget (26 ms → 6.9 ms per column at that length), every column is reserved for the whole cascade, and `element.textContent` is the complete notice at every instant, so the `aria-live` region announces the whole sentence rather than a fragment. A notice deferred minutes past boot is equally safe: the long-lived `Text` node is never replaced.
+- **DOM text is the truth, and its node NEVER moves — do not "fix" this.** The label is a `.gev-flap-text` span holding one long-lived `Text` node, plus an `aria-hidden` `.gev-flap-cells` sibling; the component's `v-flap-text` directive writes it, because Vue would patch a lone `{{ text }}` child by setting `textContent` and swap the node. The ONLY text operation for the life of the chip is `node.data = next`. Nothing is reparented, so the label is never transiently empty and the `aria-live` region never sees a removal/reinsertion pair it could announce twice. `element.textContent` is the settled string at every instant, because the cells carry no text at all: both glyphs are CSS generated content (`::before` from `data-flap-prev` = outgoing, `::after` from `data-flap-next` = incoming), which never reaches `textContent`. This keeps QA pins honest. Whether the label is on screen is read once the change has rendered, after its chip shows or hides with it; the cells go in before the browser paints.
+- **No animation loop, and exactly ONE `setTimeout` per change.** CSS `animation`/`transition` only, triggered once per text change and staggered through a per-cell `--gev-flap-delay`. The single timer is the settle that strips the cells; the width ease ends on a `transitionend`/`transitioncancel` listener, never a second timer. Idle cost is zero, there is no periodic work, and nothing requests a Cesium render or takes a render-governor hold. An unchanged label is not republished, which is required — the chips are recomputed by a 60 ms and a 500 ms ticker.
 - **Only what was visible flaps away.** An interrupted cascade (A→B cut short by C) derives each column's outgoing glyph from `visibleGlyphs()` — what that column is actually SHOWING at that instant, which for a column whose stagger has not elapsed is still A, not the pending B. `FLAP_TURN_RATIO` must track the `gev-flap-out`/`gev-flap-in` keyframe crossover in style.css.
 - **Columns never renumber mid-cascade — do not "optimise" this away.** For the whole cascade the board keeps one column per index of the LONGER string, each holding its own width; a column the new string does not reach flaps to a BLANK in place (`data-flap-next=" "`) rather than collapsing. Collapsing stacks the absolutely-positioned outgoing glyphs on one x AND lets a later glyph slide into an earlier column, which makes `visibleGlyphs()` lie and the interrupt rule flap the wrong glyph away. Pinned by "a cleared column holds its place instead of letting later glyphs slide left".
 - Length changes are eased, never snapped, and the ease is placed so it never fights the flaps (`.gev-flap-sizing`): a GROWING label reserves its columns as the cells go in and eases at the START; a SHRINKING one holds full width for the whole cascade and eases at SETTLEMENT.