feat(mesh): server name in adverts + clear-all button + CI fix

- Mesh adverts now use the node's configured server name (e.g. "ThinkPad",
  "Arch Dev") instead of DID key fragments ("Archy-z6MkmkSB")
- Added mesh.clear-all RPC to reset peers, messages, contacts, and history
- Added "Clear All" button in Mesh UI peers panel
- Both glibc and musl builds verified

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

core/archipelago/src/server.rs

@@ -156,6 +156,8 @@ impl Server {
             let signing_key = identity.signing_key();
             match crate::mesh::MeshService::new(&data_dir, signing_key, &did, &pubkey_hex).await {
                 Ok(mut mesh_service) => {
+                    // Pass the human-readable server name for mesh adverts
+                    mesh_service.set_server_name(data.server_info.name.clone());
                     let mut mesh_config = crate::mesh::load_config(&data_dir).await.unwrap_or_default();
 
                     // Auto-enable mesh if a radio is detected and no config exists yet