fix(session-options): keep Respawn and Ralph visible for Claude sessions

Since the CLI registry gave claude kind 'agent' (#476), isExternalCliRunMode() reads claude as an external CLI, so Session Options opened every Claude session on Summary and hid the Respawn and Ralph tabs and every Claude-only control (auto-resume, the respawn loop). The browser catalog now carries the registry's capabilities.external, the flag the server's isExternalCliMode() already reads, and Session Options asks that instead. run() keeps isExternalCliRunMode(): choosing a launch path is a different question, and custom agents rely on it.

src/web/public/session-ui.js

@@ -140,6 +140,13 @@ function isExternalCliRunMode(mode) {
   return EXTERNAL_CLI_MODES.has(mode) || registryCliById(mode)?.kind === 'agent';
 }
 
+// Does this session lack the Claude-only features (Respawn, Ralph)? The registry's
+// `capabilities.external`, the flag the server's isExternalCliMode() reads. Not
+// isExternalCliRunMode(): that picks a launch path, and claude is `kind: 'agent'` too.
+function isExternalCliSession(mode) {
+  return registryCliById(mode)?.external ?? isExternalCliRunMode(mode);
+}
+
 Object.assign(CodemanApp.prototype, {
   /**
    * Build envOverrides payload from case + global settings.
@@ -2430,7 +2437,7 @@ Object.assign(CodemanApp.prototype, {
     if (detachToggle) detachToggle.checked = this.hasTabDetachOverride(sessionId);
 
     // Reset to an appropriate tab — Summary for external CLIs (Respawn/Ralph are Claude-only)
-    const isAltMode = isExternalCliRunMode(session.mode);
+    const isAltMode = isExternalCliSession(session.mode);
     this.switchOptionsTab(isAltMode ? 'summary' : 'respawn');
 
     // Update respawn status display and buttons

src/web/server.ts

@@ -1713,6 +1713,7 @@ export class WebServer extends EventEmitter {
           shortBadge: entry.shortBadge,
           order: entry.order,
           kind: entry.kind,
+          external: entry.capabilities.external,
           enabled,
           available: enabled && installed,
         };