test(windows): isolate the daemon guards' rendezvous and stop hiding their failures

Every Windows guard shared ONE daemon. test_daemon_stability.py said each
section "runs under its OWN cache directory: daemon coordination is
cache-scoped" -- it is not. The rendezvous key is FNV-1a over a compile-time
domain string (service.c: cbm_daemon_rendezvous_key) under a machine-global
parent (win_default_runtime_parent -> SHGetFolderPathW(CSIDL_LOCAL_APPDATA),
which ignores the LOCALAPPDATA variable). So the guard's own `daemon stop`
and kill -9 sections, the sibling guards, and anything else on the runner
all met the same daemon, and a daemon wedged anywhere failed every check
after it. That is the shape of this week's test-windows-guards red on
DeusData#1874: lifecycle's `daemon start` connected, the UI-config handshake never
answered, and stability / hook_augment / ui_drive / cli_non_ascii went red
in a row with an orphan daemon killed at cleanup -- on a diff and a base that
were each green elsewhere.

CBM_RUNTIME_DIR is the only relocation hook (bootstrap.c, resolved in
cbm_daemon_bootstrap_endpoint_new for every product endpoint). Each stability
section now gets a private runtime parent next to its cache, created before
the binary runs -- the endpoint validates the parent and never creates it --
and the daemon inherits it from the client that spawns it. Proven on macOS:
a daemon on the default rendezvous keeps its pid across the whole guard
(three stops and a kill -9 inside it).

The reporting was hiding the cause as well:
* every SETUP FAIL printed nothing at all, and every RED printed a 300-400
  character HEAD slice, which is the allocator preamble, never the error.
  Excerpts now show the tail (1500 chars); setup paths print the daemon's
  full output.
* a subprocess timeout raised on a parallel-client worker thread was lost
  and the client reported as "rc=none" with no output; it is now kept as a
  failed result with its partial output. A section-level timeout is a
  named RED with the command and output, not a bare traceback.
* the MCP session's stderr went to DEVNULL; it now goes to a file that is
  printed when initialize never answers -- and that case is a RED against a
  running daemon, not a "setup" skip.
* exit 2 was documented and never produced. Only `daemon start` failing
  raises it now (test_daemon_lifecycle.py owns that surface as a
  regression, so the board loses nothing); main() runs every section and
  names all of the failing ones.
* test_hook_augment.py / test_cli_non_ascii_arg.py print full stdout AND
  stderr on their index-setup failures instead of 300 chars of stdout.

On POSIX (local iteration only) the namespace lives under /tmp: sun_path
caps the socket at 104 bytes on macOS and TMPDIR there is ~50 bytes deep.

Out of scope, noted: test_daemon_lifecycle.py, test_non_ascii_path.py and
test_ui_drive_listing.py still use the machine-global rendezvous; a too-long
CBM_RUNTIME_DIR on POSIX is refused (ipc.c sun_path check) with no
validation detail.

Signed-off-by: Martin Vogel <martin.vogel.tech@gmail.com>

Author: DeusData

tests/windows/test_cli_non_ascii_arg.py

@@ -73,6 +73,7 @@ def main():
         # (#1952). One retry against a fresh cache separates that from a real
         # CLI indexing failure.
         ctrl_out = ""
+        ctrl_err = ""
         for attempt in ("cache_ascii", "cache_ascii_retry"):
             env = dict(os.environ)
             env["CBM_CACHE_DIR"] = os.path.join(work, attempt)
@@ -81,14 +82,19 @@ def main():
                  json.dumps({"repo_path": ascii_repo})],
                 capture_output=True, timeout=120, env=env)
             ctrl_out = (ctrl.stdout or b"").decode("utf-8", "replace")
+            ctrl_err = (ctrl.stderr or b"").decode("utf-8", "replace")
             if '"nodes"' in ctrl_out:
                 break
-            print("SETUP: ASCII control attempt %r did not index via CLI:\n%s"
-                  % (attempt, ctrl_out[:300]))
+            # Full stdout AND stderr: the reason lives on stderr (daemon
+            # spawn/handshake diagnostics), and a head slice of stdout only
+            # ever showed the allocator preamble.
+            print("SETUP: ASCII control attempt %r did not index via CLI (rc=%s):\n"
+                  "stdout:\n%s\nstderr:\n%s"
+                  % (attempt, ctrl.returncode, ctrl_out, ctrl_err))
             time.sleep(2)
         if '"nodes"' not in ctrl_out:
-            print("SETUP FAIL: ASCII control did not index via CLI:\n%s" %
-                  ctrl_out[:300])
+            print("SETUP FAIL: ASCII control did not index via CLI:\nstdout:\n%s\nstderr:\n%s"
+                  % (ctrl_out, ctrl_err))
             return 2
 
         env2 = dict(os.environ)