Gossip mesh topology + source-based routing (#445)

* wip mesh graph

* gossip fix

* gossip works

* source-based routing wip

* log

* update spec to be explicit about intermediate hops only

* drop duplicate hops

* add to spec

* test

* forgot comma

* source routing v2

* add compression bomb protection

* v2 source routing

* fragmented packets inherit route

* update spec

* Gossip routing tmp with connection limit fixed (#569)

* fix: r8 exception for LocationManager (#566)

* fragmented packets inherit route

* update spec

* fix connection limits

* fix: deserialization issue with routed packets

* log

* dynamic fragment size

* fragment size

* add tests

* feat(gossip): implement two-way handshake for source routing edges

- Update MeshGraphService to track directed announcements
- Require bidirectional announcements for a 'confirmed' edge
- Update RoutePlanner to strictly use confirmed edges
- Update Mesh Topology debug view to show confirmed vs unconfirmed edges (solid vs dotted)

* docs: update SOURCE_ROUTING.md with two-way handshake requirement

* evict stale peers from mesh graph service

* better logging

* fix announce spe

* fix: empty route

* fix spec

* fix: compile error in DebugSettingsSheet and potential NPE in RoutePlanner

* revert

* try again

app/src/main/java/com/bitchat/android/mesh/MessageHandler.kt

@@ -286,6 +286,13 @@ class MessageHandler(private val myPeerID: String, private val appContext: andro
             previousPeerID = null
         )
         
+        // Update mesh graph from gossip neighbors (only if TLV present)
+        try {
+            val neighborsOrNull = com.bitchat.android.services.meshgraph.GossipTLV.decodeNeighborsFromAnnouncementPayload(packet.payload)
+            com.bitchat.android.services.meshgraph.MeshGraphService.getInstance()
+                .updateFromAnnouncement(peerID, nickname, neighborsOrNull, packet.timestamp)
+        } catch (_: Exception) { }
+
         Log.d(TAG, "✅ Processed verified TLV announce: stored identity for $peerID")
         return isFirstAnnounce
     }