epic: adopt features from the 2026-09 dependency upgrade #78

Adopt the new features and fixes from the dependency upgrades in #47 (G1) and #61 (G2–G14), focusing on the Claude agent SDK and the Codex SDK/CLI.

Plan: dev-doc/plan/2026-09-27-post-upgrade-sdk-feature-adoption.md (committed on main locally, not pushed yet).

Key constraint: #61 held @anthropic-ai/claude-agent-sdk at 0.3.239, so the Claude features are still unavailable. #62 unblocks the upgrade to 0.3.283, and every Claude issue depends on it. The Codex, Anthropic SDK and app-library tracks start now.

Wave 1: start now (parallel)

• fix(deps): upgrade claude-agent-sdk to 0.3.283 with Zod-safe MCP schemas #62 WS0: upgrade claude-agent-sdk to 0.3.283 (blocking)
• feat(codex): stream item.started/item.updated and render todo_list #63 X1: Codex streaming and todo_list (owns the codex/index.ts event loop)
• feat(codex): per-tool output limits for bridged MCP servers #64 X5: Codex per-tool MCP output limits
• chore(api): adopt @anthropic-ai/sdk 0.128 in direct Messages callers #65 A1: @anthropic-ai/sdk 0.128 direct callers
• feat(ui): React 19.3 <ViewTransition> for route and panel transitions #66 R1: React 19.3 <ViewTransition>
• spike: CopilotKit 1.74 / AG-UI 0.0.59 and Tauri 2.12 adoption review #67 R2: spike on CopilotKit/AG-UI and Tauri 2.12

Wave 2a: after #63

• feat(codex): honor outputFormat via TurnOptions.outputSchema #68 X2: Codex outputSchema
• feat(codex): forward user images as local_image input #69 X3: Codex image input
• feat(agent-runtimes): Codex GPT-6 models, persistent effort, cache-write usage #70 X4: Codex GPT-6 models, effort levels, cache-write usage

Wave 2b: after #62 (parallel)

• fix(agent): deny headless permission asks and un-shadow canUseTool #71 C1: deny headless permission asks, un-shadow canUseTool (decision recorded: deny by default)
• feat(agent): surface new Claude SDK stream signals #72 C2: new stream signals (the only issue that edits the message switch)
• feat(channels): send channel and scheduled prompts verbatim #73 C3: verbatim prompts for channels and schedules
• feat(chat): back conversation branches with forked SDK sessions #74 C4: back branches with forked SDK sessions (decided: Pi/Claude Code/Codex pattern, in-place branches, file restore is a separate action; adds a DB migration)
• perf(agent): measure and cut Claude first-turn latency #75 C5: first-turn latency (measure first)
• feat(mcp): per-server MCP timeouts, full Stop, sub-agent CLAUDE.md #76 C6: per-server MCP timeouts, full Stop (decided: Stop also stops background agents), omitClaudeMd
• spike: render MCP Apps ui:// resources in generative UI #77 C7: spike on MCP Apps ui://

Close-out

Update _module-lib-upgrade.md (remove the Claude SDK hold; keep the tools/list gate), update the agent-system docs, and run the full gate on main.

Parallel-agent rules

• One issue → one agent → one worktree/branch off main → one PR.
• claude/index.ts is a hotspot: new logic goes in sibling modules, and index.ts gets wiring changes only.
• Don't bump dependencies outside fix(deps): upgrade claude-agent-sdk to 0.3.283 with Zod-safe MCP schemas #62. Record needs-decision answers on the issue before starting it.
• Remove the blocked label from the C issues when fix(deps): upgrade claude-agent-sdk to 0.3.283 with Zod-safe MCP schemas #62 merges.