Slice 3 wave A: tabs model, model selector, cache delete, localStorage

- features/tabs: pure tab-workspace reducer (create/select/close/setModel/
  setTitle/deriveTitle, draft=null active) + injected-persistence runes store
- features/chat: mutable per-tab model (setModel) + delta routing guard
  (ignore foreign conversationId) + ModelSelector.svelte + DaisyUI chat bubbles
  / composer (keeps streaming <details> keying fix)
- features/conversation-cache: surface delete(conversationId) on the wrapper
  for tab-close local-forget
- adapters/local-storage: generic injected JSON localStore<T> (quota/corrupt-safe)

Verified: svelte-check 0/0, vitest 273, biome clean, build ok.

1 files changed, 14 insertions, 0 deletions

diff --git a/src/features/tabs/index.ts b/src/features/tabs/index.ts
new file mode 100644
index 0000000..c01d4ac
--- /dev/null
+++ b/src/features/tabs/index.ts
@@ -0,0 +1,14 @@
+export type { Tab, TabsState } from "./tabs";
+export {
+	activeTab,
+	closeTab,
+	createTab,
+	deriveTitle,
+	initialState,
+	newDraft,
+	selectTab,
+	setModel,
+	setTitle,
+} from "./tabs";
+export type { TabsStorage, TabsStore } from "./tabs-store.svelte";
+export { createTabsStore } from "./tabs-store.svelte";