feat(navi): address book with geocoding integration

- YAML-backed saved locations (config/address_book.yaml)
- Exact/partial alias matching with case-insensitive lookup
- Flask blueprint: /api/address_book/lookup, /api/address_book/list
- Geocoder short-circuits Photon when address book has exact match
- Test suite for lookup behavior

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

lib/address_book_api.py

@@ -0,0 +1,31 @@
+"""
+RECON Address Book API — Flask Blueprint.
+
+GET /api/address_book/lookup?q=<query>  — best match or 404
+GET /api/address_book/list              — all entries
+"""
+
+from flask import Blueprint, request, jsonify
+
+from . import address_book
+
+address_book_bp = Blueprint('address_book', __name__)
+
+
+@address_book_bp.route('/api/address_book/lookup')
+def api_address_book_lookup():
+    q = request.args.get('q', '').strip()
+    if not q:
+        return jsonify({'error': 'Missing q parameter'}), 400
+
+    result = address_book.lookup(q)
+    if result is None:
+        return '', 404
+
+    return jsonify(result)
+
+
+@address_book_bp.route('/api/address_book/list')
+def api_address_book_list():
+    entries = address_book.list_all()
+    return jsonify(entries)