feat(mesh,ui): per-message transport pill (Mesh/FIPS/Tor) + fix E2E pill

Adds a per-message transport badge to archy↔archy mesh chats and fixes the
long-broken E2E badge — both meshcore and meshtastic, styled like the existing
E2E pill.

Transport pill:
- New `MeshMessage.transport` ("lora"/"fips"/"tor"), surfaced in the UI beside
  the E2E badge (Mesh.vue transportLabel() → Mesh/FIPS/Tor, mesh-styles.css).
- Sent LoRa → "lora"; sent federation → finalized to the real leg ("fips"/"tor")
  once the background send resolves (req.send_json transport), via an id-keyed
  store update.
- Received: a post-dispatch stamp on handle_typed_envelope_direct's output
  (monotonic ids) tags both transports without threading through all 20 typed-
  dispatch sites — radio wrapper stamps "lora", federation injector stamps the
  peer's last_transport ("fips"/"tor", default tor; the inbound HTTP carries no
  FIPS-vs-Tor signal).
- Plain native/channel LoRa frames → "lora"; channel broadcasts stay non-E2E.

E2E pill fix:
- `encrypted` was hardcoded false at every MeshMessage construction site, so the
  UI badge (Mesh.vue `v-if="msg.encrypted"`) never showed. Now: federation
  envelopes are E2E (identity-signed over an encrypted transport); the meshcore
  native-DM receive path already had a real `encrypted` flag (now also tagged
  with transport). meshtastic-PKI radio E2E flag threading is a noted follow-up.

Backend cargo check + frontend vue-tsc build both green. Needs a live radio +
multi-transport pass on .116/.228 to confirm end-to-end (see
project_transport_pill / project_meshtastic_parity).

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

neode-ui/src/stores/mesh.ts

@@ -78,6 +78,9 @@ export interface MeshMessage {
   timestamp: string
   delivered: boolean
   encrypted: boolean
+  /// How the message traveled: "lora" (mesh radio), "fips", or "tor".
+  /// Drives the per-message transport pill. Absent until known.
+  transport?: string | null
   message_type?: MeshMessageTypeLabel
   // eslint-disable-next-line @typescript-eslint/no-explicit-any
   typed_payload?: Record<string, any> | null