feat: find-nearby skill and Telegram location support

Adds a 'find-nearby' skill for discovering nearby places using
OpenStreetMap (Overpass + Nominatim). No API keys needed. Works with:
- Coordinates (from Telegram location pins)
- Addresses, cities, zip codes, landmarks (auto-geocoded)
- Multiple place types (restaurant, cafe, bar, pharmacy, etc.)

Returns names, distances, cuisine, hours, addresses, and Google Maps
links (pin + directions). 184-line stdlib-only script.

Also adds Telegram location message handling:
- New MessageType.LOCATION in gateway base
- Telegram adapter handles LOCATION and VENUE messages
- Injects lat/lon coordinates into conversation context
- Prompts agent to ask what the user wants nearby

Inspired by PR #422 (reimplemented with simpler script and broader
skill scope — addresses/cities/zips, not just Telegram coordinates).

gateway/platforms/base.py

@@ -252,6 +252,7 @@ def cleanup_document_cache(max_age_hours: int = 24) -> int:
 class MessageType(Enum):
     """Types of incoming messages."""
     TEXT = "text"
+    LOCATION = "location"
     PHOTO = "photo"
     VIDEO = "video"
     AUDIO = "audio"

gateway/platforms/telegram.py

@@ -132,6 +132,10 @@ class TelegramAdapter(BasePlatformAdapter):
                 filters.COMMAND,
                 self._handle_command
             ))
+            self._app.add_handler(TelegramMessageHandler(
+                filters.LOCATION | getattr(filters, "VENUE", filters.LOCATION),
+                self._handle_location_message
+            ))
             self._app.add_handler(TelegramMessageHandler(
                 filters.PHOTO | filters.VIDEO | filters.AUDIO | filters.VOICE | filters.Document.ALL | filters.Sticker.ALL,
                 self._handle_media_message
@@ -546,6 +550,41 @@ class TelegramAdapter(BasePlatformAdapter):
         event = self._build_message_event(update.message, MessageType.COMMAND)
         await self.handle_message(event)
     
+    async def _handle_location_message(self, update: Update, context: ContextTypes.DEFAULT_TYPE) -> None:
+        """Handle incoming location/venue pin messages."""
+        if not update.message:
+            return
+
+        msg = update.message
+        venue = getattr(msg, "venue", None)
+        location = getattr(venue, "location", None) if venue else getattr(msg, "location", None)
+
+        if not location:
+            return
+
+        lat = getattr(location, "latitude", None)
+        lon = getattr(location, "longitude", None)
+        if lat is None or lon is None:
+            return
+
+        # Build a text message with coordinates and context
+        parts = ["[The user shared a location pin.]"]
+        if venue:
+            title = getattr(venue, "title", None)
+            address = getattr(venue, "address", None)
+            if title:
+                parts.append(f"Venue: {title}")
+            if address:
+                parts.append(f"Address: {address}")
+        parts.append(f"latitude: {lat}")
+        parts.append(f"longitude: {lon}")
+        parts.append(f"Map: https://www.google.com/maps/search/?api=1&query={lat},{lon}")
+        parts.append("Ask what they'd like to find nearby (restaurants, cafes, etc.) and any preferences.")
+
+        event = self._build_message_event(msg, MessageType.LOCATION)
+        event.text = "\n".join(parts)
+        await self.handle_message(event)
+
     async def _handle_media_message(self, update: Update, context: ContextTypes.DEFAULT_TYPE) -> None:
         """Handle incoming media messages, downloading images to local cache."""
         if not update.message: