feat: add session thread management (#98510)

* feat: add session thread management

Squash of codex/thread-management (025aefc3ad1) onto origin/main:
pin/archive/rename sessions via sessions.patch, archived-aware
sessions.list, lifecycle fencing, read-only archived chat, SDK +
Swift protocol support, Control UI session management.

* refactor(ui): minimal session rows with hover-revealed management

Chat picker and sidebar recents share session-row primitives: single-line
rows, relative timestamps, rename/archive/pin revealed on hover or focus,
accent pin badge for pinned rows, and an active-run spinner in the trail
slot. Sidebar floats pinned sessions above recency via the shared
comparator and gains archive/pin actions through the unified sessions-view
patch fallback. Archive eligibility is one shared policy
(canArchiveSessionRow); the sidebar/picker active-run tooltip now uses the
real sessionsView.activeRun locale key.

* fix: align session admission with mailbox-era main

Integration fixes after rebasing onto current main: sessions_list mailbox
test expectations learn the archived/pinned row fields and archived:false
list param; gateway agent admission treats a session as deleted only when
both the requested and canonical alias sets miss it (legacy bare-main
stores and exec-approval followups read under different spellings); cron
persist tests keep a consistent store across claim-guarded persist calls;
the ACP abort hook test asserts abort propagation instead of signal
identity; drop dead lifecycle writes flagged by no-useless-assignment and
fix the promise-executor return in the codex compact test.

* fix(qa): align UI e2e and shard fixtures with redesigned session rows

Sidebar session rows are wrapper divs with an inner link now: update the
navigation browser tests and chat-flow Playwright selectors. Seed a real
per-test session store for the auto-fallback admission guard instead of
depending on leftover host files at /tmp/sessions.json. Teach the
test-projects routing fixture about the suites that newly import the
shared temp-dir helper. Document the Codex thread-format contract for
archivedAt/pinnedAt (flag derived from server-stamped timestamp, epoch ms
here vs Codex epoch seconds) at the type and in the session docs.

* test: route auto-fallback suite through temp-dir helper plans

The auto-fallback suite now imports the shared temp-dir helper for its
seeded session store, so the top-level helper routing fixture must list
it in the auto-reply plan.

src/scripts/test-projects.test.ts

@@ -859,6 +859,8 @@ describe("test-projects args", () => {
         config: "test/vitest/vitest.unit-fast.config.ts",
         forwardedArgs: [],
         includePatterns: [
+          "src/agents/command/attempt-execution.shared.test.ts",
+          "src/auto-reply/reply/session-entry-persistence.test.ts",
           "src/crestodian/operations.test.ts",
           "src/install-sh-version.test.ts",
           "src/proxy-capture/store.sqlite.test.ts",
@@ -937,6 +939,7 @@ describe("test-projects args", () => {
           "src/gateway/hooks-mapping.test.ts",
           "src/gateway/server-methods/chat.abort-persistence.test.ts",
           "src/gateway/server.agent.gateway-server-agent-b.test.ts",
+          "src/gateway/server.chat.gateway-server-chat-b.test.ts",
           "src/gateway/server.sessions.permissions-hooks.test.ts",
         ],
         watchMode: false,
@@ -965,6 +968,17 @@ describe("test-projects args", () => {
         ],
         watchMode: false,
       },
+      {
+        config: "test/vitest/vitest.auto-reply.config.ts",
+        forwardedArgs: [],
+        includePatterns: [
+          "src/auto-reply/reply/get-reply-native-slash-fast-path.test.ts",
+          "src/auto-reply/reply/get-reply.auto-fallback.test.ts",
+          "src/auto-reply/reply/reply-turn-admission.test.ts",
+          "src/auto-reply/reply/session-updates.test.ts",
+        ],
+        watchMode: false,
+      },
       {
         config: "test/vitest/vitest.agents.config.ts",
         forwardedArgs: [],