Harden Infonet DM address flow and seed sync

Allow local-operator DM invite import without requiring a full admin session.

Prioritize bundled/bootstrap seed peers and shorten stale seed cooldowns for faster Infonet recovery.

Replace raw DM invite dumps with copyable signed-address controls, contact request handling, and safer sealed-send behavior while the private delivery route connects.

.env.example

@@ -67,6 +67,12 @@ ADMIN_KEY=
 # SHADOWBROKER_SLOW_FETCH_CONCURRENCY=4
 # SHADOWBROKER_STARTUP_HEAVY_CONCURRENCY=2
 
+# Infonet bootstrap/sync responsiveness. Defaults favor fast seed failure
+# detection so stale onion peers do not make the terminal look hung.
+# MESH_SYNC_TIMEOUT_S=5
+# MESH_SYNC_MAX_PEERS_PER_CYCLE=3
+# MESH_BOOTSTRAP_SEED_FAILURE_COOLDOWN_S=15
+
 # Google Earth Engine for VIIRS night lights change detection (optional).
 # pip install earthengine-api
 # GEE_SERVICE_ACCOUNT_KEY=