perf: overhaul session loading, caching, and runtime isolation (#2360)

Improve OpenChamber responsiveness under large session workloads while fixing
cache, synchronization, and persistence correctness across runtimes, projects,
directories, and worktrees.

- prioritize selected and visible sessions during bootstrap and defer
  non-critical enrichment work
- reduce redundant message loading, event processing, store publication, and
  hidden sidebar work
- prevent stale session and message requests from overwriting newer
  authoritative state
- preserve existing data when authoritative fetches fail instead of treating
  failures as successful empty responses
- scope session materialization, messages, drafts, queues, todos, pins,
  permissions, folders, tabs, Git state, and pull request data by runtime and
  directory identity
- harden runtime switching, reconnect, cleanup, mutation reconciliation, and
  persisted-state ordering
- preserve live subagent Task linkage when metadata arrives after an older
  message request or while streaming parts are suspended
- coalesce overlapping tail refreshes without losing newer refresh demand
- improve cold-session loading by moving deferrable work out of the critical
  bootstrap path
- isolate URL authentication, mobile credentials, native secrets, and other
  runtime-owned state across endpoint changes
- bound long-lived caches and remove avoidable allocations from event and
  rendering hot paths
- limit virtualization to archive collections where it improves rendering
  without disrupting active sidebar layout
- stabilize session folders, pin ordering, expanded state, and persisted
  sidebar behavior
- open skill files through the same secure editor and outside-workspace grant
  flow used by file navigation, including worktree sessions
- expand regression coverage for stale completions, runtime collisions,
  reconnect behavior, persistence races, authoritative empty results, and
  subagent refresh ordering
- document the updated synchronization, cache ownership, performance, and
  runtime-isolation invariants

packages/ui/src/stores/messageQueueStore.test.ts

@@ -0,0 +1,51 @@
+import { beforeEach, describe, expect, test } from "bun:test"
+import {
+  createMessageQueueTarget,
+  getMessageQueueKey,
+  migrateMessageQueueState,
+  parseMessageQueueKey,
+  useMessageQueueStore,
+} from "./messageQueueStore"
+
+beforeEach(() => {
+  useMessageQueueStore.setState({ queuedMessages: {}, quarantinedLegacyMessages: {} })
+})
+
+describe("message queue runtime ownership", () => {
+  test("isolates colliding session IDs by runtime and directory", () => {
+    const a = createMessageQueueTarget("session-1", "/repo", "runtime-a")!
+    const b = createMessageQueueTarget("session-1", "/repo", "runtime-b")!
+    useMessageQueueStore.getState().addToQueue(a, { content: "from A" })
+    useMessageQueueStore.getState().addToQueue(b, { content: "from B" })
+
+    expect(useMessageQueueStore.getState().getQueueForTarget(a)[0]?.content).toBe("from A")
+    expect(useMessageQueueStore.getState().getQueueForTarget(b)[0]?.content).toBe("from B")
+  })
+
+  test("round trips a composite queue key", () => {
+    const target = createMessageQueueTarget("session-1", "/repo", "runtime-a")!
+    expect(parseMessageQueueKey(getMessageQueueKey(target))).toEqual(target)
+  })
+
+  test("quarantines legacy session-only queues instead of activating them", () => {
+    const migrated = migrateMessageQueueState({
+      queuedMessages: {
+        "session-1": [{ id: "queued-1", content: "legacy", createdAt: 1 }],
+      },
+    }, 1)
+
+    expect(migrated.queuedMessages).toEqual({})
+    expect(migrated.quarantinedLegacyMessages?.["session-1"]?.[0]?.content).toBe("legacy")
+  })
+
+  test("bounds each queue to the newest 20 messages", () => {
+    const target = createMessageQueueTarget("session-1", "/repo", "runtime-a")!
+    for (let index = 0; index < 25; index += 1) {
+      useMessageQueueStore.getState().addToQueue(target, { content: `message-${index}` })
+    }
+
+    const queue = useMessageQueueStore.getState().getQueueForTarget(target)
+    expect(queue).toHaveLength(20)
+    expect(queue[0]?.content).toBe("message-5")
+  })
+})