feat(views,surface-host): Extensions sidebar view — auto-expanded surfaces + tables

views (new feature):
- pure panel-stack reducer + thin generic ViewSidebar (dropdown picker + add/remove),
  switches on view KIND, never a surface id

Extensions view (composition root):
- folds frontend modules + backend surfaces into one "Extensions" view
- frontend module list AGGREGATED from each feature's public `manifest` export
  (can't drift); no per-module version (FE features are internal to dispatch-web)
- surfaces are AUTO-SUBSCRIBED on catalog + rendered expanded (no catalog buttons)

surface-host:
- consecutive `stat` fields coalesce into one aligned label/value table (StatTable)
- generic custom-field renderer: dispatch on rendererId === "table" → SurfaceTable
  (pure parseTablePayload), so a backend `custom`/table field renders generically
- shared presentational components/Table.svelte (used by both, neither feature
  depends on the other)

store:
- auto-subscribe every catalog entry, unsubscribe vanished ones, re-subscribe all
  on reconnect; expose all received specs via `surfaces` (drops single-selection)

backend-handoff: CR-1 — emit Loaded Extensions as a custom/table field; notes
what's already covered FE-side (renderer shipped, stat-table fallback works).

1 files changed, 0 insertions, 10 deletions

diff --git a/src/features/surface-host/ui/Stat.svelte b/src/features/surface-host/ui/Stat.svelte
deleted file mode 100644
index e184dab..0000000
--- a/src/features/surface-host/ui/Stat.svelte
+++ /dev/null
@@ -1,10 +0,0 @@
-<script lang="ts">
-	import type { StatFieldView } from "../logic/types";
-
-	let { field }: { field: StatFieldView } = $props();
-</script>
-
-<dl>
-	<dt>{field.label}</dt>
-	<dd>{field.value}</dd>
-</dl>