Fix Windows Cookbook background tasks, exit statuses, and empty SSH logs wrapper (#1389)

This commit consolidates all Windows Cookbook background fixes into a single comprehensive commit based on the latest main branch.

Key fixes included:
1. React looksSuccessful Mismatch: Append 'DOWNLOAD_OK' for pip install commands in routes/cookbook_routes.py.
2. Local Windows SSH Wrapper & Log Directory Mismatch: Bypassed ssh wrappers and dynamically selected odysseus-tmux logs for local tasks in static/js/cookbookRunning.js.
3. WSL Bash Filtration: Filtered out the WSL bash stub at C:\Windows\System32\bash.exe in core/platform_compat.py.
4. Drive-Colon Path Normalization: Replaced .as_posix() with git_bash_path() in routes/shell_routes.py and src/bg_jobs.py.
5. GGUF-Only Hardware Fitting: Restructured local Windows recommendations to rank GGUF only in services/hwfit/fit.py.
6. Safe Win32 Process Liveness Probe: Replaced os.kill(pid, 0) with a safe Win32 API probe using GetExitCodeProcess in core/platform_compat.py.
7. Prebuilt llama-cpp-python Wheels: Supply the CPU extra index during compilation failure fallback.
8. Enforce UTF-8 log encoding: Set PYTHONIOENCODING=utf-8 on Windows bootstrap runners.
9. Fix Linux Llama.cpp Build script syntax error in routes/cookbook_helpers.py.
10. Page Reload Status Check: Run sys.executable instead of 'python3' to bypass Microsoft Store execution stubs on local Windows hosts.
11. Llama.cpp serve build bypass: Bypassed cmake compilation checks on local Windows and verified python bindings directly.
12. Serve Command Path Validation: Masked safe GGUF path printf subshells '' inside the serve command validator.
13. CPU Mismatch Diagnostics: Intercepted AVX2-lacking '0xc000001d' (Illegal Instruction) crashes in static/js/cookbook-diagnosis.js and guided users to Ollama.
14. Windows Pytest stability: Fixed stub import leakage in test files.

core/platform_compat.py

@@ -180,6 +180,21 @@ def _is_windows_bash_stub(path: str) -> bool:
     )
 
 
+def git_bash_path(path: str | Path) -> str:
+    """Convert a path to POSIX style suitable for Git Bash on Windows.
+
+    Transforms drive letters (e.g., 'C:\\path') to POSIX '/c/path',
+    and uses forward slashes.
+    """
+    p = Path(path)
+    p_str = p.as_posix()
+    if IS_WINDOWS and len(p_str) >= 2 and p_str[1] == ":":
+        drive = p_str[0].lower()
+        return f"/{drive}{p_str[2:]}"
+    return p_str
+
+
+
 def find_bash() -> Optional[str]:
     """Locate a real ``bash`` interpreter, or None.