Summary

• Narrow App, Terminal, and floating terminal subscriptions to active/mounted worktree slices.
• Add pure projection helpers and tests for mounted worktrees, terminal/browser tabs, browser-pane worktree IDs, and open-file slices.
• Keep TerminalPane/split-surface PTY mounts gated on workspaceSessionReady while preserving active restored browser tabs before PTY reconnect completes.

UX / Risk

• No user-visible status freshness paths are changed: Source Control, ChecksPanel, hosted review refresh, and provider IPC are untouched.
• Terminal shortcut policy and shortcut-capture notifications are untouched.
• PTY transport, SSH transport, runtime RPC, and terminal restart persistence are untouched.
• BrowserPane pre-ready rendering is browser-only and does not spawn PTYs.

Verification

• pnpm exec vitest run --config config/vitest.config.ts src/renderer/src/components/terminal/terminal-mounted-worktrees.test.ts src/renderer/src/components/terminal/terminal-tab-slices.test.ts src/renderer/src/components/terminal/terminal-browser-tab-slices.test.ts src/renderer/src/components/terminal/terminal-browser-pane-worktrees.test.ts src/renderer/src/components/terminal/active-worktree-open-files.test.ts src/renderer/src/components/floating-terminal/floating-terminal-open-files.test.ts src/renderer/src/components/floating-terminal/FloatingTerminalPanel.test.tsx src/renderer/src/components/terminal/background-terminal-worktree-mount.test.ts src/renderer/src/components/terminal/split-group-mount.test.ts src/renderer/src/components/terminal/active-terminal-repair.test.ts src/renderer/src/components/terminal/terminal-tab-actions.test.ts src/renderer/src/components/tab-group/TabGroupSplitLayout.test.ts src/renderer/src/components/terminal-pane/terminal-live-layout-reconciliation.test.ts src/renderer/src/components/terminal-pane/pty-connection.test.ts src/renderer/src/runtime/sync-runtime-graph-terminal-layout.test.ts
• pnpm exec oxlint src/renderer/src/App.tsx src/renderer/src/components/Terminal.tsx src/renderer/src/components/floating-terminal/FloatingTerminalPanel.tsx src/renderer/src/components/terminal/terminal-mounted-worktrees.ts src/renderer/src/components/terminal/terminal-mounted-worktrees.test.ts src/renderer/src/components/terminal/terminal-tab-slices.ts src/renderer/src/components/terminal/terminal-tab-slices.test.ts src/renderer/src/components/terminal/terminal-browser-tab-slices.ts src/renderer/src/components/terminal/terminal-browser-tab-slices.test.ts src/renderer/src/components/terminal/terminal-browser-pane-worktrees.ts src/renderer/src/components/terminal/terminal-browser-pane-worktrees.test.ts src/renderer/src/components/terminal/active-worktree-open-files.ts src/renderer/src/components/terminal/active-worktree-open-files.test.ts src/renderer/src/components/floating-terminal/floating-terminal-open-files.ts src/renderer/src/components/floating-terminal/floating-terminal-open-files.test.ts
• pnpm typecheck
• pnpm test
• pnpm exec electron-vite build --mode e2e
• SKIP_BUILD=1 pnpm exec playwright test tests/e2e/terminal-panes.spec.ts tests/e2e/terminal-typing-latency.spec.ts tests/e2e/terminal-shortcuts.spec.ts tests/e2e/terminal-restart-persistence.spec.ts tests/e2e/browser-tab.spec.ts tests/e2e/tabs.spec.ts --config tests/playwright.config.ts --project electron-headless
• git diff --check