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>

src/config/auth-config.ts

@@ -31,5 +31,10 @@ export const AUTH_FAILURE_WINDOW_MS = 15 * 60 * 1000;
 // Hooks
 // ============================================================================
 
-/** Timeout for Claude Code hook curl commands (ms) */
-export const HOOK_TIMEOUT_MS = 10000;
+/**
+ * Timeout for Claude Code hook curl commands, in SECONDS: the hook `timeout`
+ * field is seconds (the CLI multiplies by 1000). The predecessor constant
+ * `HOOK_TIMEOUT_MS = 10000` fed the same field, so those hooks effectively had a
+ * ~2.8-hour timeout; 10 seconds is the originally intended budget.
+ */
+export const HOOK_TIMEOUT_SECONDS = 10;