Always used shortest path in advert burst

app/CLAUDE.md

@@ -531,13 +531,12 @@ The `POST /api/contacts/{key}/telemetry` endpoint fetches status, neighbors, and
 ### Request Flow
 
 1. Verify contact exists and is a repeater (type=2)
-2. Sync contacts from radio with `ensure_contacts()`
-3. Remove and re-add contact with flood mode (clears stale auth state)
-4. Send login with password
-5. Request status with retries (3 attempts, 10s timeout)
-6. Fetch neighbors with `fetch_all_neighbours()` (handles pagination)
-7. Fetch ACL with `req_acl_sync()`
-8. Resolve pubkey prefixes to contact names from database
+2. Add contact to radio with stored path data (from advertisements)
+3. Send login with password
+4. Request status with retries (3 attempts, 10s timeout)
+5. Fetch neighbors with `fetch_all_neighbours()` (handles pagination)
+6. Fetch ACL with `req_acl_sync()`
+7. Resolve pubkey prefixes to contact names from database
 
 ### ACL Permission Levels
 
@@ -626,7 +625,14 @@ if txt_type == 1:
 ### Helper Function
 
 `prepare_repeater_connection()` handles the login dance:
-1. Sync contacts from radio
-2. Remove contact if exists (clears stale auth)
-3. Re-add with flood mode (`out_path_len=-1`)
-4. Send login with password
+1. Add contact to radio with stored path from DB (`out_path`, `out_path_len`)
+2. Send login with password
+3. Wait for key exchange to complete
+
+### Contact Path Tracking
+
+When advertisements are received, path data is extracted and stored:
+- `last_path`: Hex string of routing path bytes
+- `last_path_len`: Number of hops (-1=flood/unknown, 0=direct, >0=hops through repeaters)
+
+**Shortest path selection**: When receiving echoed advertisements within 60 seconds, the shortest path is kept. This ensures we use the most efficient route when multiple paths exist.

app/packet_processor.py

@@ -309,17 +309,41 @@ async def _process_advertisement(
         return
 
     # Extract path info from packet
-    path_len = packet_info.path_length
-    path_hex = packet_info.path.hex() if packet_info.path else ""
+    new_path_len = packet_info.path_length
+    new_path_hex = packet_info.path.hex() if packet_info.path else ""
+
+    # Try to find existing contact
+    existing = await ContactRepository.get_by_key(advert.public_key)
+
+    # Determine which path to use: keep shorter path if heard recently (within 60s)
+    # This handles advertisement echoes through different routes
+    PATH_FRESHNESS_SECONDS = 60
+    use_existing_path = False
+
+    if existing and existing.last_seen:
+        path_age = timestamp - existing.last_seen
+        existing_path_len = existing.last_path_len if existing.last_path_len >= 0 else float('inf')
+
+        # Keep existing path if it's fresh and shorter (or equal)
+        if path_age <= PATH_FRESHNESS_SECONDS and existing_path_len <= new_path_len:
+            use_existing_path = True
+            logger.debug(
+                "Keeping existing shorter path for %s (existing=%d, new=%d, age=%ds)",
+                advert.public_key[:12], existing_path_len, new_path_len, path_age
+            )
+
+    if use_existing_path:
+        path_len = existing.last_path_len
+        path_hex = existing.last_path or ""
+    else:
+        path_len = new_path_len
+        path_hex = new_path_hex
 
     logger.debug(
         "Parsed advertisement from %s: %s (role=%d, lat=%s, lon=%s, path_len=%d)",
         advert.public_key[:12], advert.name, advert.device_role, advert.lat, advert.lon, path_len
     )
 
-    # Try to find existing contact
-    existing = await ContactRepository.get_by_key(advert.public_key)
-
     # Use device_role from advertisement for contact type (1=Chat, 2=Repeater, 3=Room, 4=Sensor)
     # Use advert.timestamp for last_advert (sender's timestamp), receive timestamp for last_seen
     contact_type = advert.device_role if advert.device_role > 0 else (existing.type if existing else 0)