feat(devtools)!: reuse the built-in Terminals dock via ctx.terminals

[antfubot]

Summary

Implements plan 02-terminals-reuse from the Vite DevTools integration series. Nuxt DevTools stops shipping its own @xterm terminal UI + RPC and instead surfaces terminal sessions through the devframe terminals host (ctx.terminals), so they render in Vite DevTools' built-in Terminals dock (which auto-hides when empty). The Nuxt "Terminals" tab is removed.

Existing modules keep working via a compat shim, and a new opt-in interactive PTY path is added.

What changed

Server bridge (server-rpc/terminals.ts, rewritten)

• Bridges the devtools:terminal:* hooks onto ctx.terminals instead of maintaining its own Map + RPC:
  • register → a read-only DevframeTerminalSession carrying a ReadableStream (registered via ctx.terminals.register). Re-registration resets/clears in place, so startSubprocess().clear()/restart() still work.
  • write → controller.enqueue(data); exit → close stream + update(status); remove → dispose + remove the session.
  • New devtools:terminal:spawn hook → ctx.terminals.startChildProcess (output-only) or ctx.terminals.startPtySession (interactive PTY, zigpty with graceful pipe fallback).
• Terminals registered before the kit connects are buffered and replayed inside the devtools:ready callback.

Kit surface (@nuxt/devtools-kit)

• Added SpawnTerminalOptions, the devtools:terminal:spawn hook, and a startDevToolsTerminal() helper (opt-in PTY).
• Dropped getTerminals/getTerminalDetail/runTerminalAction + onTerminalData from the RPC types (kept onTerminalExit). TerminalState/TerminalInfo/TerminalAction and the devtools:terminal:* module-facing hooks are preserved.

Internal producers — module-install / analyze-build / npm-update already spawn via startChildProcess; they now broadcast onTerminalExit on process exit so their transient UI state (installing-modules, "Building…", update spinner) still clears. Exit-driven cleanup is not lost.

Client — deleted the terminals.vue tab, TerminalPage.vue, TerminalView.vue; removed useTerminals, useCurrentTerminalId, the onTerminalData handler, and all /modules/terminals navigation (replaced with a "follow the output in the Terminals dock" hint). Removed the @xterm/* deps from package.json, pnpm-workspace.yaml, and the client nuxt.config.ts bundling/optimizeDeps; refreshed the lockfile.

Docs — documented startDevToolsTerminal() and refreshed the "Terminals tab" references.

Notes / breaking changes

• New major: the bespoke Nuxt terminals RPC (getTerminals/getTerminalDetail/runTerminalAction) and the @xterm UI are removed. Module-facing hooks (devtools:terminal:register/write/remove/exit) and startSubprocess() continue to work via the shim.
• The startSubprocess/getProcess() deprecation codes (NDT_DEP_0004/0001) already shipped; this PR swaps the underlying implementation rather than adding new codes.

Verification

pnpm lint, pnpm typecheck, pnpm build, and pnpm test:unit all pass.

This PR was created with the help of an agent.