Release v0.51.236 — Release HD (stage-q7) (#3491)

## Release v0.51.236 — Release HD (stage-q7)

First Phase 3 (deep-review) release — picked by the 3-factor framework (contributor × impact × mitigated-risk): high-impact (#1952 native Windows support), backend-only (no screenshots), well-mitigated risk (POSIX path provably unchanged), from a contributor active this session (@rodboev, #3446/#3486 shipped earlier today).

### Added
| PR | Author | Fix |
|----|--------|-----|
| #1952 | @rodboev | Native Windows support for `bootstrap.py` + the embedded terminal: POSIX-only `fcntl`/`termios`/`select` guarded behind `_TERMINAL_SUPPORTED`; terminal entry points raise `NotImplementedError`/no-op on Windows; bootstrap Windows block → warning; auto-install errors clearly on native Windows (WSL unaffected); foreground uses `Popen`+exit on Windows instead of `os.execv`. **POSIX behavior unchanged on every path.** |

### Absorbed on the way in (fix-it-ourselves, reviewed fresh)
- `subprocess.CREATE_NEW_PROCESS_GROUP` → `getattr(subprocess, ..., 0)` — the constant is Windows-only, so a win32-simulating test `AttributeError`'d on Linux. Mirrors the `SO_EXCLUSIVEADDRUSE` getattr guard.
- Fixed 2 over-reaching tests in `test_windows_native_support.py` — one was launching a **real installer subprocess** via an unstubbed `subprocess.run` (now stubbed; harness 2.8s vs 80s); removed unused imports.
- Updated `test_onboarding_static.py` — it asserted the OLD "Native Windows is not supported" hard-block string this PR intentionally replaces; now asserts the new experimental-warning + auto-install guard.
- Help-text accuracy: `--foreground` help now describes the Windows Popen path (Opus nit).

### Gate results
- **Full pytest suite**: 7478 passed, 9 skipped, 3 xpassed, **0 failed**
- **ruff forward gate**: CLEAN
- **browser-smoke gate**: CLEAN (gate hardened mid-release to auto-detect the cached chromium revision)
- **Codex (regression)**: SAFE TO SHIP (simulated `sys.platform=win32`, verified POSIX modules not imported + all terminal guards complete + POSIX foreground still uses execv)
- **Opus (correctness)**: SAFE TO SHIP (POSIX path provably unchanged, all fcntl/termios/select guarded, Popen+exit correct; noted inherent-Windows trade-offs that aren't PR bugs)

Note: the Windows *runtime* path can't be executed on the Linux CI box; it was reviewed statically by both reviewers + the contributor's 209-line test (win32 simulated via monkeypatch). Linux/POSIX no-regression is fully verified.

Closes #1952.

Co-authored-by: rodboev <rodboev@users.noreply.github.com>

bootstrap.py

@@ -92,9 +92,9 @@ def is_wsl() -> bool:
 
 def ensure_supported_platform() -> None:
     if platform.system() == "Windows" and not is_wsl():
-        raise RuntimeError(
-            "Native Windows is not supported for this bootstrap yet. "
-            "Please run it from Linux, macOS, or inside WSL2."
+        info(
+            "Warning: Native Windows bootstrap is experimental. "
+            "Embedded terminal and auto-install are not supported."
         )
 
 
@@ -270,6 +270,11 @@ def hermes_command_exists() -> bool:
 
 
 def install_hermes_agent() -> None:
+    if platform.system() == "Windows" and not is_wsl():
+        raise RuntimeError(
+            "Auto-install is not supported on native Windows. "
+            "Install hermes-agent manually first."
+        )
     info(f"Hermes Agent not found. Attempting install via {INSTALLER_URL}")
     subprocess.run(
         ["/bin/bash", "-lc", f"curl -fsSL {INSTALLER_URL} | bash"], check=True
@@ -316,8 +321,10 @@ def parse_args() -> argparse.Namespace:
         "--foreground",
         action="store_true",
         help=(
-            "Run server.py in this process (via os.execv) instead of spawning a "
-            "child. Use this under launchd / systemd / supervisord so the "
+            "Run server.py in this process (via os.execv on POSIX; via a "
+            "Popen child + exit on Windows, where execv can't replace the "
+            "process image) instead of spawning a detached child. Use this "
+            "under launchd / systemd / supervisord so the "
             "supervisor sees the long-lived server as the original child. "
             "Implies --no-browser. Skips the post-launch health probe — the "
             "supervisor's own KeepAlive / Restart=on-failure handles liveness."
@@ -444,8 +451,19 @@ def main() -> int:
                 f"Set HERMES_WEBUI_PYTHON to a working interpreter or fix "
                 f"the agent venv at {agent_dir}."
             )
-        # os.execv replaces the current process image. Anything after this line
-        # only runs if execv itself fails (it raises OSError on failure).
+        # os.execv replaces the current process image. On Windows, execv
+        # spawns a new process instead of replacing (Python calls CreateProcess),
+        # orphaning it from any supervisor. Use Popen + exit there instead.
+        if sys.platform == "win32":
+            # CREATE_NEW_PROCESS_GROUP only exists in the subprocess module on
+            # Windows; resolve it defensively (0 = no extra flags) so this line
+            # can't AttributeError if reached on a non-Windows interpreter
+            # (e.g. a win32-simulating test) — mirrors the getattr() guard used
+            # for SO_EXCLUSIVEADDRUSE.
+            _CREATE_NEW_PROCESS_GROUP = getattr(subprocess, "CREATE_NEW_PROCESS_GROUP", 0)
+            subprocess.Popen([python_exe, server_path],
+                             creationflags=_CREATE_NEW_PROCESS_GROUP)
+            sys.exit(0)
         os.execv(python_exe, [python_exe, server_path])
         # Unreachable — execv either replaces the process or raises.
         raise RuntimeError("os.execv returned unexpectedly")