fix(hooks,test): harden background rewake, fix hook timeout units, stabilize CI teardown

Follow-ups from the PR #175/#176 reviews:

- Rewake helper self-terminates on its own 6h deadline and when orphaned,
  instead of relying on Claude Code to reap the poller
- Rewake marker versioned (V2) with a version-agnostic ownership prefix, so
  future script updates replace older handlers instead of duplicating them;
  regression test covers the V1 to V2 swap
- HOOK_TIMEOUT_MS renamed to HOOK_TIMEOUT_SECONDS = 10: the hook timeout
  field is seconds (the CLI multiplies by 1000), so the curl hooks have
  effectively had a ~2.8h timeout since COD-54
- Test echo PTY switches to raw mode: each input byte echoes exactly once
  (tty line discipline doubled every line and buffered until Enter)
- test/setup.ts: drain in-flight console-log rpc forwards before environment
  teardown (fixes the EnvironmentTeardownError that failed CI twice on the
  merge commit with all 3820 tests passing), clean the temp home on process
  exit (fully-skipped files leaked it), fix the Windows Playwright cache
  fallback path
- test/webview-proxy.test.ts: stop naming the vitest environment directive in
  prose; vitest matches it inside comments and silently ran the whole file
  under the jsdom environment while the comment claimed node
- CLAUDE.md: document the temp-HOME and echo-PTY test isolation

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

test/webview-proxy.test.ts

@@ -487,7 +487,10 @@ describe('runtimeUrlShim', () => {
  * 404s on Codeman's own root while the dashboard's fetch-driven data loads fine.
  *
  * Node environment on purpose, like test/markdown-sanitizer.test.ts: a per-file
- * `@vitest-environment jsdom` externalizes node builtins under vite.
+ * jsdom environment directive would externalize node builtins under vite. The
+ * directive is deliberately not written out here, even in prose: vitest scans
+ * comments for it, and naming it flipped this whole file to the jsdom
+ * environment while this comment claimed the opposite.
  */
 describe('runtimeUrlShim DOM sinks', () => {
   const body = runtimeUrlShim(PREFIX)