feat(protocol): add Paste request type for bracketed-paste events

feat(engine): summarize agent completion progress in UI notifications

feat(main): enable and disable bracketed paste support in terminal

fix(app_config): store API key from file as fallback for Claude provider

refactor(workflow): remove unnecessary card separator in workflow panel

src/model/app_config.rs

@@ -154,13 +154,22 @@ struct ClaudeSettings {
 /// than through its settings file, so reading only the file misses them.
 fn detect_claude_settings_provider() -> Option<ProviderConfig> {
     // Prefer the file, then fall back to env vars.
-    let (base_url, _key) = claude_credentials_from_file()
+    let (base_url, key) = claude_credentials_from_file()
         .or_else(claude_credentials_from_env)?;
     Some(ProviderConfig {
         api_base: base_url,
+        // Keep the env-var name so runtime env overrides still work.
         api_key_env: Some("ANTHROPIC_API_KEY".to_string()),
         default_model: None,
-        default_api_key: None,
+        // Store the key read from the file as a direct fallback.
+        // Without this, subagent/engine.rs resolve_provider_config() falls
+        // through to std::env::var("ANTHROPIC_API_KEY") which is only
+        // injected into the Claude Code process — not into zesdex.  Workflow
+        // nodes therefore got an empty key and failed with
+        // "no API key configured for provider 'claude'", even though the
+        // main agent succeeded (it has a DEFAULT_API_KEY fallback that
+        // subagents intentionally do not have).
+        default_api_key: Some(key),
     })
 }