feat(tabs): cross-device tab sync via conversation lifecycle

Consume the conversation lifecycle handoff ([email protected], [email protected]).
Re-pinned file: deps + re-mirrored .dispatch/*.reference.md.

- fetchOpenConversations() on connect: GET /conversations?status=active,idle
  restores the tab bar across devices (merges with localStorage — opens new
  tabs, removes closed ones, updates titles from backend)
- conversation.statusChanged WS handler: closed → removeTabLocally (no
  re-POST); active → open tab + spinner; idle → update status map
- conversation.compacted WS handler: dispose stale store + cache, reload
  history from server
- TabBar shows a spinner on active conversations (statusFor prop)
- closeTab refactored to use removeTabLocally (extracted cleanup)
- conformance guards + WS adapter tests cover all 3 new WsServerMessage types

686 tests green.

1 files changed, 6 insertions, 0 deletions

diff --git a/src/features/tabs/ui/TabBar.svelte b/src/features/tabs/ui/TabBar.svelte
index 812a663..9d224b9 100644
--- a/src/features/tabs/ui/TabBar.svelte
+++ b/src/features/tabs/ui/TabBar.svelte
@@ -5,12 +5,15 @@
 	let {
 		tabs,
 		activeConversationId,
+		statusFor,
 		onSelect,
 		onClose,
 		onNewDraft,
 	}: {
 		tabs: readonly Tab[];
 		activeConversationId: string | null;
+		/** Returns the conversation's lifecycle status, or undefined when unknown. */
+		statusFor?: (conversationId: string) => string | undefined;
 		onSelect: (conversationId: string) => void;
 		onClose: (conversationId: string) => void;
 		onNewDraft: () => void;
@@ -84,6 +87,9 @@
 					{handles.get(tab.conversationId) ?? tab.conversationId}
 				</span>
 				<span class="min-w-0 flex-1 truncate text-left">{tab.title}</span>
+				{#if statusFor?.(tab.conversationId) === "active"}
+					<span class="loading loading-spinner loading-xs shrink-0 text-primary"></span>
+				{/if}
 				<button
 					class="btn btn-ghost btn-xs shrink-0"
 					aria-label="Close tab"