feat(mcp): align MCP surface with current app state

- Add Journey addon tools (list, get, entries, contributors, suggestions,
  available trips, create/update/delete journey and entries, reorder,
  contributors CRUD, preferences, share link management)
- Add Journey resources (trek://journeys and sub-resources)
- Split transport (flight/train/car/cruise) into dedicated tools with
  endpoints[] and needs_review support; narrow reservation types to
  non-transport only
- Add airport lookup tools (search_airports, get_airport) under geo:read
- Add import_places_from_url and bulk_delete_places to places tools
- Add journey:read/write/share OAuth scopes (27 total) with translations
  across all 15 locales
- Default end_day to start_day when creating a transport (MCP + UI)
- Fix MCP.md drift: addon gates, removed files resource, corrected
  get_trip_summary description, todos under Packing addon

server/src/mcp/tools/mapsWeather.ts

@@ -1,5 +1,6 @@
 import { McpServer } from '@modelcontextprotocol/sdk/server/mcp';
 import { z } from 'zod';
+import { findByIata, searchAirports } from '../../services/airportService';
 import { searchPlaces, getPlaceDetails, reverseGeocode, resolveGoogleMapsUrl } from '../../services/mapsService';
 import { getWeather, getDetailedWeather } from '../../services/weatherService';
 import {
@@ -110,4 +111,38 @@ export function registerMapsWeatherTools(server: McpServer, userId: number, scop
       }
     }
   );
+
+  // --- AIRPORTS ---
+
+  if (canGeo) server.registerTool(
+    'search_airports',
+    {
+      description: 'Search for airports by name, city, or IATA code. Returns matching airports with IATA code, name, city, country, coordinates, and timezone. Use before create_transport (flight) to get the correct IATA code and timezone for endpoints.',
+      inputSchema: {
+        query: z.string().min(1).max(200).describe('Airport name, city, or IATA code (e.g. "zurich", "ZRH", "charles de gaulle")'),
+        limit: z.number().int().min(1).max(50).optional().default(10),
+      },
+      annotations: TOOL_ANNOTATIONS_READONLY,
+    },
+    async ({ query, limit }) => {
+      const airports = searchAirports(query, limit ?? 10);
+      return ok({ airports });
+    }
+  );
+
+  if (canGeo) server.registerTool(
+    'get_airport',
+    {
+      description: 'Get a single airport by its IATA code. Returns name, city, country, coordinates, and timezone.',
+      inputSchema: {
+        iata: z.string().length(3).toUpperCase().describe('IATA airport code (e.g. "ZRH", "AMS", "CDG")'),
+      },
+      annotations: TOOL_ANNOTATIONS_READONLY,
+    },
+    async ({ iata }) => {
+      const airport = findByIata(iata);
+      if (!airport) return { content: [{ type: 'text' as const, text: 'Airport not found.' }], isError: true };
+      return ok({ airport });
+    }
+  );
 }