chore(codex): Add PreToolUse hook for graphify search context

Integrates a PreToolUse hook that provides context from the 'graphify' knowledge graph.
When the AI is about to use search commands (e.g., `grep`, `find`, `ripgrep`),
it will be prompted to consult `GRAPH_REPORT.md` if a graph exists, guiding it to
leverage structured knowledge before searching raw files.

.codex/hooks.json

@@ -0,0 +1,15 @@
+{
+  "hooks": {
+    "PreToolUse": [
+      {
+        "matcher": "Bash",
+        "hooks": [
+          {
+            "type": "command",
+            "command": "CMD=$(python3 -c \"import json,sys; d=json.load(sys.stdin); print(d.get('tool_input',d).get('command',''))\" 2>/dev/null || true); set -- $CMD; case \"$1\" in grep|egrep|fgrep|rg|ripgrep|find|fd|ack|ag) [ -f graphify-out/graph.json ] && echo '{\"hookSpecificOutput\":{\"hookEventName\":\"PreToolUse\",\"additionalContext\":\"graphify: Knowledge graph exists. Read graphify-out/GRAPH_REPORT.md for god nodes and community structure before searching raw files.\"}}' || true ;; esac"
+          }
+        ]
+      }
+    ]
+  }
+}