fix(tui): reserve /runtime and block local tool-loop fallback

src/frontends/tui/commands.test.ts

@@ -113,6 +113,11 @@ describe('parseCommand', () => {
     expect(parseCommand('/backend ollama')).toEqual({ type: 'backend', provider: 'ollama' });
   });
 
+  it('parses /runtime command', () => {
+    expect(parseCommand('/runtime')).toEqual({ type: 'runtime' });
+    expect(parseCommand('/runtime status')).toEqual({ type: 'runtime', input: 'status' });
+  });
+
   it('parses /transfer command', () => {
     expect(parseCommand('/transfer telegram')).toEqual({ type: 'transfer', target: 'telegram' });
     expect(parseCommand('/transfer')).toEqual({ type: 'transfer', target: '' });
@@ -146,6 +151,7 @@ describe('getHelpText', () => {
     expect(help).toContain('/help');
     expect(help).toContain('/paste');
     expect(help).toContain('/model');
+    expect(help).toContain('/runtime');
     expect(help).toContain('/tools');
     expect(help).toContain('/research');
     expect(help).toContain('/council');
@@ -215,6 +221,11 @@ describe('getCommandCompletions', () => {
     const completions = getCommandCompletions('/council pre');
     expect(completions).toEqual(['/council preflight']);
   });
+
+  it('completes /runtime command', () => {
+    const completions = getCommandCompletions('/ru');
+    expect(completions).toContain('/runtime');
+  });
 });
 
 describe('isToolInventoryQuery', () => {

src/frontends/tui/commands.ts

@@ -14,6 +14,7 @@ export type Command =
   | { type: 'verbose' }
   | { type: 'model'; name?: string; providerModel?: string }
   | { type: 'backend'; provider?: string }
+  | { type: 'runtime'; input?: string }
   | { type: 'login'; provider?: string }
   | { type: 'transfer'; target: string }
   | { type: 'pair'; action?: 'generate' | 'list' | 'revoke'; args?: string }
@@ -154,6 +155,15 @@ export function parseCommand(input: string): Command | null {
     return { type: 'backend', provider };
   }
 
+  // Runtime backend mode control (daemon/channel command; reserved in TUI)
+  if (trimmed === '/runtime') {
+    return { type: 'runtime' };
+  }
+  if (trimmed.startsWith('/runtime ')) {
+    const input = trimmed.slice('/runtime '.length).trim();
+    return { type: 'runtime', input };
+  }
+
   // Transfer
   if (trimmed === '/transfer') {
     return { type: 'transfer', target: '' };
@@ -223,6 +233,7 @@ Commands:
   /model [name]          Show or switch model tier (local, default, fast, complex)
   /model <tier> <p/m>    Change tier's provider/model (e.g. /model default anthropic/claude-sonnet-4)
   /backend [provider]    Show or switch local backend (ollama, llamacpp)
+  /runtime [args]        Runtime backend mode control (daemon/channel sessions)
   /research <task>       Delegate a task to the configured research agent
   /council <task>        Run the councils pipeline for a task
   /council preflight     Check council tier routing, endpoint/auth mode, and probe latency
@@ -261,6 +272,7 @@ export const SLASH_COMMANDS = [
   '/tools',
   '/model',
   '/backend',
+  '/runtime',
   '/research',
   '/council',
   '/reset',
@@ -293,6 +305,7 @@ export const COMMAND_TOOLTIPS: Record<string, string> = {
   '/tools': 'Show authoritative runtime tool list for this session',
   '/model': 'Show or switch model (local, default, fast, complex)',
   '/backend': 'Show or switch local backend (ollama, llamacpp)',
+  '/runtime': 'Runtime backend mode control (daemon/channel command; not local TUI backend switch)',
   '/research': 'Delegate a task to the configured research agent',
   '/council': 'Run the councils pipeline for a task; use "/council preflight" for route/auth checks',
   '/reset': 'Clear conversation history',

src/frontends/tui/components/App.tsx

@@ -563,6 +563,18 @@ export function App({
         return;
       }
 
+      case 'runtime': {
+        pushAssistantMessage(
+          'Runtime backend mode command is not available in fullscreen TUI mode.\n'
+            + 'Use it in daemon/channel sessions:\n'
+            + '/runtime status\n'
+            + '/runtime activate pi\n'
+            + '/runtime deactivate pi\n'
+            + '/runtime use config',
+        );
+        return;
+      }
+
       case 'login': {
         const provider = (command.provider ?? '').trim().toLowerCase();
         if (!provider) {

src/frontends/tui/minimal.test.ts

@@ -403,6 +403,29 @@ describe('MinimalTui backend command', () => {
     }
   });
 
+  it('prints guidance when /runtime is invoked in TUI mode', async () => {
+    const mockSession = {
+      id: 'test',
+      getHistory: () => [],
+      addMessage: vi.fn(),
+      clear: vi.fn(),
+      replaceHistory: vi.fn(),
+    };
+    const logSpy = vi.spyOn(console, 'log').mockImplementation(() => {});
+    try {
+      const tui = new MinimalTui({
+        session: asSession(mockSession),
+        modelClient: asModelClient({}),
+        systemPrompt: 'test',
+      });
+
+      await minimalTuiPrivates(tui).handleCommand({ type: 'runtime', input: 'status' });
+      expect(logSpy).toHaveBeenCalledWith(expect.stringContaining('Runtime backend mode command is not available in this TUI mode.'));
+    } finally {
+      logSpy.mockRestore();
+    }
+  });
+
   it('collects multiline input from /paste and sends as one message', async () => {
     const mockSession = {
       id: 'test',

src/frontends/tui/minimal.ts

@@ -524,6 +524,10 @@ export class MinimalTui {
         await this.handleBackendCommand(command.provider);
         break;
 
+      case 'runtime':
+        this.handleRuntimeCommand(command.input);
+        break;
+
       case 'login':
         await this.handleLoginCommand(command.provider);
         break;
@@ -895,6 +899,16 @@ export class MinimalTui {
     console.log(`${colors.gray}Switched to backend: ${provider}${colors.reset}\n`);
   }
 
+  private handleRuntimeCommand(_input?: string): void {
+    console.log(`${colors.gray}Runtime backend mode command is not available in this TUI mode.${colors.reset}`);
+    console.log(`${colors.gray}Use it in daemon/channel sessions:${colors.reset}`);
+    console.log('  /runtime status');
+    console.log('  /runtime activate pi');
+    console.log('  /runtime deactivate pi');
+    console.log('  /runtime use config');
+    console.log('');
+  }
+
   private async stopBackend(provider: string): Promise<void> {
     try {
       const { exec } = await import('child_process');