fix: harden daemon and embed-lock process identity on Windows

[ilepn]

PR: fix: harden daemon and embed-lock process identity on Windows

Summary

• Replace bare daemon/embed PIDs with qmd-process/v1 records containing the
  PID, role, and an OS-issued process-start token.
• Use Windows CIM process creation timestamps with hidden PowerShell execution,
  Linux /proc/<pid>/stat field 22, and ps lstart on other POSIX systems.
• Publish daemon identity only after the HTTP listener binds, observe early
  child exit, and verify the exact same identity immediately before signalling.
• Treat live pre-upgrade numeric state as unverifiable and fail closed instead
  of orphaning a daemon or stealing an active embed lock; role-specific POSIX
  command-line checks retain safe recognition where the owner can be proven.
• Pass the TSX loader as a file URL and hide spawned Windows process windows.
• Publish embed locks atomically, fail closed on fresh malformed state, and
  reclaim only an unchanged malformed lock after a 30-second grace period.

If the Windows CIM probe cannot obtain a process-start token, QMD writes a
legacy PID record and deliberately leaves it untouched while that PID remains
live. This degraded mode favors avoiding signals or lock theft against an
unrelated process; normal lifecycle management resumes after the process exits
or its ownership is independently reconciled.

Why

The previous command-line inspection could not identify native Windows QMD
processes reliably. Bare PIDs are also unsafe after PID reuse and allowed
status/start/stop and embed-lock recovery to act on unrelated processes.

Review-driven hardening

Two earlier adversarial Opus passes challenged upgrade compatibility, PID
reuse, protected-process probes, lock publication/recovery, runtime-specific
daemon launching, and Windows test coverage. A final Claude ultrareview then
found and verified two POSIX/signal-exit defects; both were corrected, and a
second ultrareview of the amended candidate completed with no findings. The
revision uses role-aware legacy checks, CIM creation timestamps, atomic lock
publication with a non-hardlink fallback, guarded malformed-state recovery,
and a Bun-native TypeScript child path.

Verification

• bun run lint
• bun run test:types
• Node/Vitest and Bun 1.4.0-canary.1 process-identity and embed-lock tests:
  17 passed under each runtime
• native Windows mcp http daemon group: 13 passed under Node and 13 under
  Bun 1.4.0-canary.1
• git diff --check

Local branch

• base: dbfd0b4736aeaf761d1a16ca8e424f071df8feb9
• commit: 355f4c8
• branch: fix/windows-process-identity