chore: add Claude Project Knowledge sync tooling

- scripts/sync-claude-docs.sh with sync/check/list/help subcommands
- scripts/install-claude-sync-hooks.sh for one-time hook setup
- .githooks/post-commit auto-syncs on dev-doc changes
- .githooks/pre-push warns (non-blocking) on stale sync
- .claude-sync.conf lists 11 synced documents
- SYNC_MANIFEST.md provides drift-detection anchor for Claude Chat
- package.json: npm run sync:docs | sync:check
- .gitignore excludes .claude-sync/ output directory

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

scripts/install-claude-sync-hooks.sh

@@ -0,0 +1,27 @@
+#!/usr/bin/env bash
+set -euo pipefail
+
+# One-time installer for the Claude Project Knowledge sync hooks.
+# Points git at the versioned .githooks/ directory and ensures hooks are executable.
+
+REPO_ROOT="$(git rev-parse --show-toplevel 2>/dev/null || true)"
+if [ -z "${REPO_ROOT}" ]; then
+  printf '%s\n' "❌ Not inside a git repository." >&2
+  exit 1
+fi
+cd "${REPO_ROOT}"
+
+if [ ! -d ".githooks" ]; then
+  printf '%s\n' "❌ .githooks/ directory missing at repo root." >&2
+  exit 1
+fi
+
+git config core.hooksPath .githooks
+chmod +x .githooks/post-commit .githooks/pre-push
+
+cat <<'EOF'
+✅ Claude sync hooks installed.
+   • post-commit: auto-syncs on dev-doc changes
+   • pre-push: warns if .claude-sync/ is stale
+Run once to verify: bash scripts/sync-claude-docs.sh sync
+EOF