ci(windows): curate the fix-wave regression tests into the windows-latest run

The windows-free-tests curated set is derived (POSIX-fragility regex scan
+ explicit deny list), and two of this wave's Windows regression files
were auto-excluded on false-positive pattern hits:

- browse/test/file-permissions.test.ts tripped the POSIX-mode-bitmask
  pattern, but every `mode & 0o777` assertion is platform-guarded — and
  the file carries the win32-only icacls-by-SID regression tests, which
  can only ever execute on windows-latest.
- browse/test/terminal-agent-owner-watchdog.test.ts tripped the
  spawn(['bun','run',...]) pattern whose reason is the Playwright-bound
  browse server; it actually spawns terminal-agent.ts (fs/path/crypto +
  local helpers only, no Playwright at module scope), and the owner-PID
  orphan leak it pins was reported on Windows (#2019).

Adds a KNOWN_WINDOWS_SAFE force-include list (mirror of
KNOWN_WINDOWS_INCOMPATIBLE, each entry carrying its false-positive
rationale) consulted before the pattern scan, and makes the
owner-watchdog test's throwaway owner process Windows-portable
(process.execPath instead of `sleep`, which a bare runner may not have).

The wave's other new files need no wiring: process-liveness-windows and
the bun-polyfill windowsHide/exited tests pass curation automatically;
setup-runtime-lib-command self-skips on win32 by design (its Windows
branch is exercised by simulating IS_WINDOWS=1 under bash), so
force-including it would add a permanently-skipped file.

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

browse/test/terminal-agent-owner-watchdog.test.ts

@@ -41,7 +41,13 @@ describe('terminal-agent owner lifecycle', () => {
     const stateFile = path.join(stateDir, 'browse.json');
     fs.writeFileSync(stateFile, JSON.stringify({ token: 'test-token' }));
 
-    const owner = Bun.spawn(['sleep', '30'], { stdio: ['ignore', 'ignore', 'ignore'] });
+    // process.execPath (the running bun) instead of `sleep`: coreutils are
+    // not guaranteed on a bare windows-latest runner, and this test is on the
+    // Windows CI curated list — the owner-orphan leak it pins is a Windows bug.
+    const owner = Bun.spawn(
+      [process.execPath, '-e', 'await Bun.sleep(30000)'],
+      { stdio: ['ignore', 'ignore', 'ignore'] },
+    );
     spawned.push(owner);
     const agent = Bun.spawn(['bun', 'run', AGENT_SCRIPT], {
       env: {