fix #651: hook-check exits silently instead of emitting unsupported additionalContext

Codex Desktop rejects hookSpecificOutput.additionalContext on PreToolUse.
hook-check is now a no-op — graph guidance reaches the agent via AGENTS.md/skill.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

graphify/__main__.py

@@ -1510,23 +1510,9 @@ def main() -> None:
             sys.exit(1)
 
     elif cmd == "hook-check":
-        # Shell-agnostic PreToolUse hook entry point for Codex (and any platform
-        # where embedding Python/bash inline in a JSON hook command is fragile).
-        # Prints the hookSpecificOutput JSON if graph.json exists, exits 0 silently
-        # if not. Works on Windows PowerShell, cmd.exe, macOS, and Linux.
-        graph = Path("graphify-out") / "graph.json"
-        if graph.exists():
-            import json as _json
-            print(_json.dumps({
-                "hookSpecificOutput": {
-                    "hookEventName": "PreToolUse",
-                    "additionalContext": (
-                        "graphify: Knowledge graph exists. "
-                        "Read graphify-out/GRAPH_REPORT.md for god nodes and "
-                        "community structure before searching raw files."
-                    ),
-                }
-            }))
+        # Codex Desktop rejects hookSpecificOutput.additionalContext on PreToolUse.
+        # Keep this as a cross-platform no-op so installed hooks never break Bash
+        # tool calls. Graph guidance reaches the agent via AGENTS.md / skill instead.
         sys.exit(0)
     elif cmd == "check-update":
         if len(sys.argv) < 3:

tests/test_hooks.py

@@ -123,3 +123,22 @@ def test_hook_skips_head_on_exe():
     """Hook script must skip shebang extraction for .exe binaries (Windows)."""
     from graphify.hooks import _PYTHON_DETECT
     assert "*.exe) _SHEBANG=" in _PYTHON_DETECT or '*.exe)' in _PYTHON_DETECT
+
+
+def test_hook_check_no_additionalContext(tmp_path):
+    """graphify hook-check must not emit additionalContext — Codex Desktop rejects it."""
+    import sys
+    out = tmp_path / "graphify-out"
+    out.mkdir()
+    (out / "graph.json").write_text("{}", encoding="utf-8")
+
+    result = subprocess.run(
+        [sys.executable, "-m", "graphify", "hook-check"],
+        cwd=tmp_path,
+        capture_output=True,
+        text=True,
+    )
+
+    assert result.returncode == 0
+    assert result.stdout == ""
+    assert result.stderr == ""