Fix Codex ACP startup failures stuck as running tools

[jonathanKingston]

Codex ACP reports an MCP startup failure as a single tool_call carrying status: failed and its diagnostic. Copse discarded that initial state and waited for a later update that never arrives, leaving identical “Startup” rows spinning indefinitely.

Preserve initial tool output and terminal status by emitting the creation followed by the existing update path. Keep the MCP server name in startup labels, so failures appear as docs startup or issue_tracker startup with their original diagnostics.

Closes #2494.

Validation:

• Added a real ACP SDK transport fixture replaying the one-event failure emitted by codex-acp 1.10.0, plus adapter and renderer-controller regressions.
• 521 focused ACP, controller, and tool-display tests passed; pnpm run build passed.
• Focused Electron eval passed and the screenshot was visually inspected: distinct failed servers, readable diagnostics, and no activity spinners.
• Oracle-selected Electron run (high confidence): 61/65 specs passed, including the new startup regression and existing MCP labels, ACP recovery, tool activity, and tool rollup specs. Failures were hook-cards (wait timeout), mermaid-parity (SVG geometry), pane-loading (loading UI assertion), and staged-diff-ui (timeouts/missing proposed section).
• Full pnpm run check: all static gates passed; 9,267 of 9,296 unit tests passed. The 29 failures hit deadlines in unchanged hook suites (after-file-edit, before-submit-prompt, diff-apply, permission-decision, post-turn-review, session-start, stop, and subagent).
• Local Electron runs use an untracked config overriding only the browser version to Chromium 152, matching Electron 44; the base config still pins Chromium 150.

GitHub CI is currently blocked in precheck: pnpm audit --audit-level=high reports GHSA-7q85-xj36-vmfc for the existing adm-zip@0.6.0 dependency through Rampart → Transformers → onnxruntime-node. The dependency manifest and lockfile are identical to main.

[github-actions]

🖥️ PR preview

• Marketing site
• Browser demo
  Interactive, with a mocked backend — jump to a scenario:
• Builds a cupcake site
• Agent-proposed edits open the Changes panel
• Markdown list indentation
• Unattended container run
• Responsive composer footer
• Subagent display visual reference
• Subagent stays ungrouped beside reading tools
• Semantic search subagent markdown
• Light-theme approval with a bright accent
• Light-theme syntax, fills, and selection
• Grouped outside-sandbox command approval
• Remote desktop discovered-port list with one selected
• Settings scroll + sticky footer geometry
• Per-model reasoning / temperature / top-p
• Thread switch hydration notice
• Thread switch hydration failure
• Apple Development test profile
• Chat layout styling
  _{Static demo of the renderer against a mock API — the browser pane, terminal, and all main-process IPC are stubbed, so it never proves main-process behaviour. Rebuilt whenever a push changes the demo bundle; these links go live once the queued deploy lands, shortly after this comment. Removed when the PR closes.}

[copse-release-bot]

Reference screenshots ready for review

Review GitHub’s image diffs in screenshot PR #2707.
Merge it (or enable auto-merge) to apply the accepted PNGs to codex/fix-acp-startup-tools.

Rendered for a17fc5867b4f by CI run 35476282234; the immutable artifact is reference-screenshot-candidates-35476282234.

If this source branch moves, a later successful render closes the stale review PR and replaces this link.