fix(mesh): route ContentRef over federation when >160B

mesh.send-content was failing with "Message too large for LoRa: 624
bytes (max 160)" because a single ContentRef envelope (cid + onion +
cap_token + thumb) dwarfs a LoRa frame. Add a federation Tor fallback:

- New POST /archipelago/mesh-typed endpoint accepts
  {from_pubkey, typed_envelope_b64, signature}, verifies ed25519 over
  the raw wire bytes, and injects the decoded envelope into MeshState
  via a new MeshService::inject_typed_from_federation helper. This
  shares the same dispatch match as LoRa receives via a new pub(crate)
  handle_typed_envelope_direct extracted from handle_typed_message.
- MeshService::send_typed_wire_via_federation POSTs the signed wire to
  a peer's onion over TOR_SOCKS_PROXY and records a local Sent record.
- handle_mesh_send_content looks up the peer's onion in federation
  storage and routes via federation when available, falling back to
  LoRa only when no federation presence is known (still fails on
  oversized — chunking is Phase 4).

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

core/archipelago/src/api/handler/mod.rs

@@ -267,6 +267,15 @@ impl ApiHandler {
                 Self::handle_node_message(body_bytes).await
             }
 
+            // Mesh typed envelope relay over federation — peers POST
+            // pre-encoded TypedEnvelope wire bytes here when the envelope is
+            // too large for a single LoRa frame (primarily ContentRef). No
+            // session auth: the body carries a pubkey + ed25519 signature
+            // over the wire bytes which we verify before dispatching.
+            (Method::POST, "/archipelago/mesh-typed") => {
+                Self::handle_mesh_typed_relay(self.rpc_handler.clone(), body_bytes).await
+            }
+
             // Blob upload — local/session use only. Session-authenticated so
             // only the node owner can push attachments into the blob store.
             (Method::POST, "/api/blob") => {