chore: import upstream snapshot with attribution

hooks/hooks.json

@@ -0,0 +1,35 @@
+{
+  "SessionStart": [
+    {
+      "matcher": "",
+      "hooks": [
+        {
+          "type": "command",
+          "command": "cat >/dev/null || true; code-review-graph status",
+          "timeout": 10
+        }
+      ]
+    }
+  ],
+  "PostToolUse": [
+    {
+      "matcher": "EnterWorktree",
+      "hooks": [
+        {
+          "type": "command",
+          "command": "cat >/dev/null || true; code-review-graph build >/dev/null 2>&1 &"
+        }
+      ]
+    },
+    {
+      "matcher": "Write|Edit|Bash",
+      "hooks": [
+        {
+          "type": "command",
+          "command": "cat >/dev/null || true; code-review-graph update --skip-flows",
+          "timeout": 30
+        }
+      ]
+    }
+  ]
+}

hooks/session-start.sh

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+#!/bin/bash
+# Checks for the code-review-graph knowledge graph and outputs
+# guidance for Claude Code at the start of every session.
+
+# Drain stdin so large hook payloads do not cause BrokenPipeError (#493).
+cat >/dev/null || true
+
+DB_PATH=".code-review-graph/graph.db"
+
+if [ -f "$DB_PATH" ]; then
+    cat <<'INSTRUCTIONS'
+[code-review-graph] Knowledge graph is available.
+
+When answering questions about this codebase, prefer using the code-review-graph MCP tools before scanning files manually:
+- Use semantic_search_nodes_tool to find classes, functions, or types by name or keyword.
+- Use query_graph_tool with patterns like callers_of, callees_of, imports_of, importers_of, children_of, tests_for, inheritors_of, or file_summary to explore relationships.
+- Use get_impact_radius_tool to understand the blast radius of changes.
+- Use get_review_context_tool for token-efficient review context.
+- Fall back to Grep/Glob/Read only when the graph does not cover what you need.
+
+This saves significant tokens by avoiding full codebase scans.
+INSTRUCTIONS
+else
+    echo "[code-review-graph] No knowledge graph found. Run /code-review-graph:build-graph to parse this codebase and enable graph-powered queries."
+fi