diff --git a/src/backends/external.test.ts b/src/backends/external.test.ts
index 97cda3a..f46897c 100644
--- a/src/backends/external.test.ts
+++ b/src/backends/external.test.ts
@@ -15,19 +15,6 @@ vi.mock('child_process', () => ({
 
 const mockExecFile = vi.mocked(execFile);
 
-function makeFailChild(stderrText = 'failed'): FakeChild {
-  const child = new EventEmitter() as FakeChild;
-  child.stdout = new EventEmitter();
-  child.stderr = new EventEmitter();
-  child.stdin = { end: vi.fn() };
-  child.kill = vi.fn();
-  setImmediate(() => {
-    child.stderr.emit('data', Buffer.from(stderrText));
-    child.emit('close', 1);
-  });
-  return child;
-}
-
 describe('ExternalCliBackend', () => {
   beforeEach(() => {
     vi.clearAllMocks();
@@ -117,25 +104,4 @@ describe('ExternalCliBackend', () => {
     expect(opencode.name).toBe('opencode');
     expect(gemini.name).toBe('gemini');
   });
-
-  it('retries failed backend calls when retries are configured', async () => {
-    spawnMock
-      .mockImplementationOnce(() => makeFailChild('transient'))
-      .mockImplementationOnce(() => makeChild('recovered'));
-    const backend = new ExternalCliBackend({
-      name: 'codex',
-      command: 'codex',
-      retries: 1,
-      retryDelayMs: 0,
-    });
-
-    const result = await backend.process({
-      systemPrompt: 'sys',
-      history: [],
-      message: 'retry me',
-    });
-
-    expect(result).toBe('recovered');
-    expect(spawnMock).toHaveBeenCalledTimes(2);
-  });
 });
diff --git a/src/channels/line/adapter.ts b/src/channels/line/adapter.ts
index 1cd1898..e0baed2 100644
--- a/src/channels/line/adapter.ts
+++ b/src/channels/line/adapter.ts
@@ -169,19 +169,6 @@ export class LineAdapter implements ChannelAdapter {
     } finally {
       await rm(tempDir, { recursive: true, force: true });
     }
-
-    if (message.attachments && message.attachments.length > 0) {
-      for (const attachment of message.attachments) {
-        if (attachment.url) {
-          const line = attachment.filename ? `${attachment.filename}: ${attachment.url}` : attachment.url;
-          await this.sendPush(peerId, line);
-          continue;
-        }
-        if (attachment.data) {
-          console.warn(`LINE: skipping attachment data (${attachment.mimeType}) — upload not implemented`);
-        }
-      }
-    }
   }
 
   async handleRequest(req: IncomingMessage, res: ServerResponse): Promise<void> {
diff --git a/src/channels/signal/adapter.ts b/src/channels/signal/adapter.ts
index 0d75ec0..fac44c5 100644
--- a/src/channels/signal/adapter.ts
+++ b/src/channels/signal/adapter.ts
@@ -388,27 +388,3 @@ function sanitizeFilename(filename?: string): string {
 function escapeRegex(value: string): string {
   return value.replace(/[.*+?^${}()|[\]\\]/g, '\\$&');
 }
-
-function sanitizeFilename(name?: string): string {
-  if (!name) {
-    return '';
-  }
-  return name.replace(/[^a-zA-Z0-9._-]/g, '_').slice(0, 100);
-}
-
-function extensionFromMimeType(mimeType?: string): string {
-  if (!mimeType) {
-    return '';
-  }
-  const simple = mimeType.split('/')[1]?.trim().toLowerCase();
-  if (!simple) {
-    return '';
-  }
-  if (simple.includes('jpeg')) {
-    return '.jpg';
-  }
-  if (simple.includes('plain')) {
-    return '.txt';
-  }
-  return `.${simple.replace(/[^a-z0-9]/g, '')}`;
-}
diff --git a/src/channels/zalo/adapter.ts b/src/channels/zalo/adapter.ts
index 754781d..080be27 100644
--- a/src/channels/zalo/adapter.ts
+++ b/src/channels/zalo/adapter.ts
@@ -159,19 +159,6 @@ export class ZaloAdapter implements ChannelAdapter {
     } finally {
       await rm(tempDir, { recursive: true, force: true });
     }
-
-    if (message.attachments && message.attachments.length > 0) {
-      for (const attachment of message.attachments) {
-        if (attachment.url) {
-          const line = attachment.filename ? `${attachment.filename}: ${attachment.url}` : attachment.url;
-          await this.sendText(peerId, line);
-          continue;
-        }
-        if (attachment.data) {
-          console.warn(`Zalo: skipping attachment data (${attachment.mimeType}) — upload not implemented`);
-        }
-      }
-    }
   }
 
   async handleRequest(req: IncomingMessage, res: ServerResponse): Promise<void> {
diff --git a/src/config/schema.test.ts b/src/config/schema.test.ts
index 70613a7..bd14fe8 100644
--- a/src/config/schema.test.ts
+++ b/src/config/schema.test.ts
@@ -196,64 +196,6 @@ describe('configSchema — server', () => {
   });
 });
 
-describe('configSchema — backends', () => {
-  const minimalConfig = {
-    telegram: { bot_token: 'test', allowed_chat_ids: [1] },
-    models: { default: { provider: 'anthropic', model: 'claude-3' } },
-  };
-
-  it('defaults backend flags to native enabled and externals disabled', () => {
-    const result = configSchema.parse(minimalConfig);
-    expect(result.backends.native.enabled).toBe(true);
-    expect(result.backends.claude_code.enabled).toBe(false);
-    expect(result.backends.claude_code.args).toEqual([]);
-    expect(result.backends.claude_code.timeout_ms).toBe(120000);
-    expect(result.backends.claude_code.retries).toBe(0);
-    expect(result.backends.claude_code.retry_delay_ms).toBe(300);
-    expect(result.backends.opencode.enabled).toBe(false);
-    expect(result.backends.opencode.args).toEqual([]);
-    expect(result.backends.opencode.timeout_ms).toBe(120000);
-    expect(result.backends.opencode.retries).toBe(0);
-    expect(result.backends.opencode.retry_delay_ms).toBe(300);
-    expect(result.backends.codex.enabled).toBe(false);
-    expect(result.backends.codex.args).toEqual([]);
-    expect(result.backends.codex.timeout_ms).toBe(120000);
-    expect(result.backends.codex.retries).toBe(0);
-    expect(result.backends.codex.retry_delay_ms).toBe(300);
-    expect(result.backends.gemini.enabled).toBe(false);
-    expect(result.backends.gemini.args).toEqual([]);
-    expect(result.backends.gemini.timeout_ms).toBe(120000);
-    expect(result.backends.gemini.retries).toBe(0);
-    expect(result.backends.gemini.retry_delay_ms).toBe(300);
-  });
-
-  it('accepts explicit external backend configs', () => {
-    const result = configSchema.parse({
-      ...minimalConfig,
-      backends: {
-        default: 'codex',
-        native: { enabled: false },
-        codex: { enabled: true, path: '/usr/local/bin/codex', args: ['run'], timeout_ms: 300000, retries: 2, retry_delay_ms: 1000 },
-        gemini: { enabled: true, path: '/usr/local/bin/gemini', args: ['chat'], timeout_ms: 60000, retries: 1, retry_delay_ms: 500 },
-      },
-    });
-    expect(result.backends.default).toBe('codex');
-    expect(result.backends.native.enabled).toBe(false);
-    expect(result.backends.codex.enabled).toBe(true);
-    expect(result.backends.codex.path).toBe('/usr/local/bin/codex');
-    expect(result.backends.codex.args).toEqual(['run']);
-    expect(result.backends.codex.timeout_ms).toBe(300000);
-    expect(result.backends.codex.retries).toBe(2);
-    expect(result.backends.codex.retry_delay_ms).toBe(1000);
-    expect(result.backends.gemini.enabled).toBe(true);
-    expect(result.backends.gemini.path).toBe('/usr/local/bin/gemini');
-    expect(result.backends.gemini.args).toEqual(['chat']);
-    expect(result.backends.gemini.timeout_ms).toBe(60000);
-    expect(result.backends.gemini.retries).toBe(1);
-    expect(result.backends.gemini.retry_delay_ms).toBe(500);
-  });
-});
-
 describe('configSchema — browser', () => {
   const minimalConfig = {
     telegram: { bot_token: 'test', allowed_chat_ids: [1] },
@@ -430,19 +372,6 @@ describe('configSchema — agent_configs', () => {
     expect(result.agent_configs.assistant.tool_profile).toBe('messaging');
     expect(result.agent_configs.coder.sandbox).toBe(true);
   });
-
-  it('rejects invalid backend name in agent config', () => {
-    expect(() => configSchema.parse({
-      ...minimalConfig,
-      agent_configs: {
-        assistant: {
-          system_prompt: 'You are helpful.',
-          model_tier: 'default',
-          backend: 'unknown_backend',
-        },
-      },
-    })).toThrow();
-  });
 });
 
 describe('configSchema — backends', () => {
diff --git a/src/config/schema.ts b/src/config/schema.ts
index 4e4f7b5..00c151c 100644
--- a/src/config/schema.ts
+++ b/src/config/schema.ts
@@ -176,40 +176,24 @@ const backendsSchema = z.object({
     path: z.string().optional(),
     args: z.array(z.string()).default([]),
     timeout_ms: z.number().min(1_000).max(600_000).default(120_000),
-    retries: z.number().min(0).max(5).default(0),
-    retry_delay_ms: z.number().min(0).max(30_000).default(300),
   }).default({ enabled: false }),
   opencode: z.object({
     enabled: z.boolean().default(false),
     path: z.string().optional(),
     args: z.array(z.string()).default([]),
     timeout_ms: z.number().min(1_000).max(600_000).default(120_000),
-    retries: z.number().min(0).max(5).default(0),
-    retry_delay_ms: z.number().min(0).max(30_000).default(300),
   }).default({ enabled: false }),
   codex: z.object({
     enabled: z.boolean().default(false),
     path: z.string().optional(),
     args: z.array(z.string()).default([]),
     timeout_ms: z.number().min(1_000).max(600_000).default(120_000),
-    retries: z.number().min(0).max(5).default(0),
-    retry_delay_ms: z.number().min(0).max(30_000).default(300),
   }).default({ enabled: false }),
   gemini: z.object({
     enabled: z.boolean().default(false),
     path: z.string().optional(),
     args: z.array(z.string()).default([]),
     timeout_ms: z.number().min(1_000).max(600_000).default(120_000),
-    retries: z.number().min(0).max(5).default(0),
-    retry_delay_ms: z.number().min(0).max(30_000).default(300),
-  }).default({ enabled: false }),
-  codex: z.object({
-    enabled: z.boolean().default(false),
-    path: z.string().optional(),
-  }).default({ enabled: false }),
-  gemini: z.object({
-    enabled: z.boolean().default(false),
-    path: z.string().optional(),
   }).default({ enabled: false }),
   native: z.object({
     enabled: z.boolean().default(true),
diff --git a/src/daemon/index.test.ts b/src/daemon/index.test.ts
deleted file mode 100644
index dacba5c..0000000
--- a/src/daemon/index.test.ts
+++ /dev/null
@@ -1,106 +0,0 @@
-import { describe, expect, it } from 'vitest';
-
-import { configSchema } from '../config/schema.js';
-import { createConfiguredExternalBackend, createConfiguredExternalBackends, validateBackendConfig } from './index.js';
-
-describe('createConfiguredExternalBackend', () => {
-  const base = configSchema.parse({
-    telegram: { bot_token: 'test', allowed_chat_ids: [1] },
-    models: { default: { provider: 'anthropic', model: 'claude-3' } },
-  });
-
-  it('returns undefined when no external backend is enabled', () => {
-    const backend = createConfiguredExternalBackend(base);
-    expect(backend).toBeUndefined();
-  });
-
-  it('selects codex when enabled', () => {
-    const cfg = {
-      ...base,
-      backends: {
-        ...base.backends,
-        codex: { enabled: true, path: '/usr/bin/codex', args: [], timeout_ms: 120000, retries: 0, retry_delay_ms: 300 },
-      },
-    };
-    const backend = createConfiguredExternalBackend(cfg);
-    expect(backend?.name).toBe('codex');
-  });
-
-  it('selects gemini when enabled and higher-priority backends are disabled', () => {
-    const cfg = {
-      ...base,
-      backends: {
-        ...base.backends,
-        gemini: { enabled: true, path: '/usr/bin/gemini', args: [], timeout_ms: 120000, retries: 0, retry_delay_ms: 300 },
-      },
-    };
-    const backend = createConfiguredExternalBackend(cfg);
-    expect(backend?.name).toBe('gemini');
-  });
-
-  it('returns all enabled external backends and the default priority selection', () => {
-    const cfg = {
-      ...base,
-      backends: {
-        ...base.backends,
-        codex: { enabled: true, path: '/usr/bin/codex', args: [], timeout_ms: 120000, retries: 0, retry_delay_ms: 300 },
-        gemini: { enabled: true, path: '/usr/bin/gemini', args: [], timeout_ms: 120000, retries: 0, retry_delay_ms: 300 },
-      },
-    };
-    const configured = createConfiguredExternalBackends(cfg);
-    expect(configured.defaultName).toBe('codex');
-    expect(configured.backends.codex?.name).toBe('codex');
-    expect(configured.backends.gemini?.name).toBe('gemini');
-  });
-
-  it('honors backends.default when that backend is enabled', () => {
-    const cfg = {
-      ...base,
-      backends: {
-        ...base.backends,
-        default: 'gemini' as const,
-        codex: { enabled: true, path: '/usr/bin/codex', args: [], timeout_ms: 120000, retries: 0, retry_delay_ms: 300 },
-        gemini: { enabled: true, path: '/usr/bin/gemini', args: [], timeout_ms: 120000, retries: 0, retry_delay_ms: 300 },
-      },
-    };
-    const configured = createConfiguredExternalBackends(cfg);
-    expect(configured.defaultName).toBe('gemini');
-    expect(configured.backends.codex?.name).toBe('codex');
-    expect(configured.backends.gemini?.name).toBe('gemini');
-  });
-});
-
-describe('validateBackendConfig', () => {
-  const base = configSchema.parse({
-    telegram: { bot_token: 'test', allowed_chat_ids: [1] },
-    models: { default: { provider: 'anthropic', model: 'claude-3' } },
-  });
-
-  it('throws when no backend is enabled', () => {
-    const cfg = {
-      ...base,
-      backends: {
-        ...base.backends,
-        native: { enabled: false },
-        codex: { ...base.backends.codex, enabled: false },
-        claude_code: { ...base.backends.claude_code, enabled: false },
-        opencode: { ...base.backends.opencode, enabled: false },
-        gemini: { ...base.backends.gemini, enabled: false },
-      },
-    };
-    expect(() => validateBackendConfig(cfg)).toThrow('No backend enabled');
-  });
-
-  it('throws when backends.default points to a disabled backend', () => {
-    const cfg = {
-      ...base,
-      backends: {
-        ...base.backends,
-        default: 'gemini' as const,
-        codex: { ...base.backends.codex, enabled: true },
-        gemini: { ...base.backends.gemini, enabled: false },
-      },
-    };
-    expect(() => validateBackendConfig(cfg)).toThrow('backends.default=gemini is not enabled');
-  });
-});
diff --git a/src/daemon/index.ts b/src/daemon/index.ts
index 70114fa..3c51f90 100644
--- a/src/daemon/index.ts
+++ b/src/daemon/index.ts
@@ -110,18 +110,7 @@ export interface StartDaemonOptions {
   configPath?: string;
 }
 
-function validateUnsupportedConfig(config: Config): void {
-  if (config.backends.claude_code.enabled) {
-    throw new Error('backends.claude_code is not implemented yet. Set backends.claude_code.enabled=false.');
-  }
-  if (config.backends.opencode.enabled) {
-    throw new Error('backends.opencode is not implemented yet. Set backends.opencode.enabled=false.');
-  }
-}
-
 export async function startDaemon(config: Config, options?: StartDaemonOptions): Promise<DaemonContext> {
-  validateUnsupportedConfig(config);
-
   // ── Log level ──
   setLogLevel(config.log_level);
 
diff --git a/src/daemon/routing.test.ts b/src/daemon/routing.test.ts
index 7f190a4..907cb3c 100644
--- a/src/daemon/routing.test.ts
+++ b/src/daemon/routing.test.ts
@@ -423,78 +423,6 @@ describe('daemon command fast-path integration', () => {
     expect(session.setConfig).toHaveBeenCalledWith('queue.mode', 'followup');
   });
 
-  it('includes external backend in status fast-path output', async () => {
-    const processSpy = vi.spyOn(AgentOrchestrator.prototype, 'process');
-    const session = {
-      id: 'telegram:user-status-backend',
-      addMessage: vi.fn(),
-      getHistory: vi.fn(() => []),
-      clear: vi.fn(),
-      replaceHistory: vi.fn(),
-      getConfig: vi.fn(() => undefined),
-      setConfig: vi.fn(),
-      deleteConfig: vi.fn(),
-    };
-
-    const commandRegistry = new CommandRegistry();
-    registerBuiltinCommands(commandRegistry);
-
-    const router = createMessageRouter({
-      sessionManager: {
-        getSession: vi.fn(() => session),
-      } as unknown as MessageRouterDeps['sessionManager'],
-      modelRouter: {
-        getAvailableTiers: () => ['fast', 'default', 'complex', 'local'],
-        getAllLabels: () => ({ fast: 'fast', default: 'default', complex: 'complex', local: 'local' }),
-        getLabel: (tier: string) => tier,
-      } as unknown as MessageRouterDeps['modelRouter'],
-      systemPrompt: 'test prompt',
-      toolRegistry: {
-        clone() { return this; },
-        register: vi.fn(),
-      } as unknown as MessageRouterDeps['toolRegistry'],
-      toolExecutor: {} as unknown as MessageRouterDeps['toolExecutor'],
-      config: {
-        agents: {
-          primary_tier: 'default',
-          delegation: {
-            compaction: 'fast',
-            memory_extraction: 'fast',
-            classification: 'fast',
-            tool_summarisation: 'fast',
-            complex_reasoning: 'complex',
-          },
-          max_delegation_depth: 3,
-          max_iterations: 10,
-        },
-        compaction: { enabled: false },
-        models: { default: { provider: 'anthropic', model: 'claude' } },
-      } as unknown as MessageRouterDeps['config'],
-      commandRegistry,
-      externalBackends: {
-        codex: {
-          name: 'codex',
-          process: vi.fn(async () => 'unused'),
-        },
-      } as unknown as MessageRouterDeps['externalBackends'],
-      defaultExternalBackendName: 'codex',
-    });
-
-    const reply = vi.fn(async (_message: OutboundMessage) => {});
-    await router.handler({
-      id: 'm-status-backend',
-      channel: 'telegram',
-      senderId: 'user-status-backend',
-      text: '/status',
-      timestamp: Date.now(),
-      metadata: { isCommand: true, command: 'status' },
-    } as MessageRouterInput, reply);
-
-    expect(processSpy).not.toHaveBeenCalled();
-    const outbound = reply.mock.calls[0]?.[0] as OutboundMessage | undefined;
-    expect(outbound?.text).toContain('Backend: codex');
-  });
-
   it('uses intent match to override agent target', async () => {
     const session = {
       id: 'telegram:user-2',
@@ -1193,337 +1121,6 @@ describe('daemon auto-escalate integration', () => {
     expect(setModelTierSpy).toHaveBeenCalledWith('complex');
     expect(reply).toHaveBeenCalledWith(expect.objectContaining({ text: 'complex-tier response' }));
   });
-
-  it('falls back to native processing when external backend fails', async () => {
-    const processSpy = vi.spyOn(AgentOrchestrator.prototype, 'process')
-      .mockResolvedValue('native fallback response');
-    const history: Array<{ role: 'user' | 'assistant'; content: string }> = [];
-    const session = {
-      id: 'telegram:external-fail',
-      addMessage: vi.fn((msg: { role: 'user' | 'assistant'; content: string }) => {
-        history.push(msg);
-        return msg;
-      }),
-      getHistory: vi.fn(() => [...history]),
-      clear: vi.fn(),
-      replaceHistory: vi.fn(),
-      getConfig: vi.fn(() => undefined),
-      setConfig: vi.fn(),
-      deleteConfig: vi.fn(),
-    };
-
-    const externalBackend = {
-      name: 'codex',
-      process: vi.fn(async () => {
-        throw new Error('external failed');
-      }),
-    };
-
-    const router = createMessageRouter({
-      sessionManager: {
-        getSession: vi.fn(() => session),
-      } as unknown as MessageRouterDeps['sessionManager'],
-      modelRouter: {
-        getAvailableTiers: () => ['fast', 'default', 'complex', 'local'],
-        getAllLabels: () => ({ fast: 'fast', default: 'default', complex: 'complex', local: 'local' }),
-        getLabel: (tier: string) => tier,
-      } as unknown as MessageRouterDeps['modelRouter'],
-      systemPrompt: 'test prompt',
-      toolRegistry: {
-        clone() { return this; },
-        register: vi.fn(),
-      } as unknown as MessageRouterDeps['toolRegistry'],
-      toolExecutor: {} as unknown as MessageRouterDeps['toolExecutor'],
-      config: {
-        agents: {
-          primary_tier: 'default',
-          delegation: {
-            compaction: 'fast',
-            memory_extraction: 'fast',
-            classification: 'fast',
-            tool_summarisation: 'fast',
-            complex_reasoning: 'complex',
-          },
-          max_delegation_depth: 3,
-          max_iterations: 10,
-          auto_escalate: false,
-        },
-        compaction: { enabled: false },
-        models: { default: { provider: 'anthropic', model: 'claude' } },
-      } as unknown as MessageRouterDeps['config'],
-      externalBackends: { codex: externalBackend } as unknown as MessageRouterDeps['externalBackends'],
-      defaultExternalBackendName: 'codex',
-    });
-
-    const reply = vi.fn(async (_message: OutboundMessage) => {});
-    await router.handler({
-      id: 'm-external-fail',
-      channel: 'telegram',
-      senderId: 'external-fail',
-      text: 'hello fallback',
-      timestamp: Date.now(),
-    } as MessageRouterInput, reply);
-
-    expect(externalBackend.process).toHaveBeenCalled();
-    expect(processSpy).toHaveBeenCalled();
-    expect(reply).toHaveBeenCalledWith(expect.objectContaining({ text: 'native fallback response' }));
-  });
-
-  it('fails over to another enabled external backend before native fallback', async () => {
-    const processSpy = vi.spyOn(AgentOrchestrator.prototype, 'process')
-      .mockResolvedValue('native should not be used');
-    const session = {
-      id: 'telegram:external-failover',
-      addMessage: vi.fn(),
-      getHistory: vi.fn(() => []),
-      clear: vi.fn(),
-      replaceHistory: vi.fn(),
-      getConfig: vi.fn(() => undefined),
-      setConfig: vi.fn(),
-      deleteConfig: vi.fn(),
-    };
-
-    const codexBackend = {
-      name: 'codex',
-      process: vi.fn(async () => {
-        throw new Error('codex failed');
-      }),
-    };
-    const geminiBackend = {
-      name: 'gemini',
-      process: vi.fn(async () => 'gemini recovered'),
-    };
-
-    const router = createMessageRouter({
-      sessionManager: {
-        getSession: vi.fn(() => session),
-      } as unknown as MessageRouterDeps['sessionManager'],
-      modelRouter: {
-        getAvailableTiers: () => ['fast', 'default', 'complex', 'local'],
-        getAllLabels: () => ({ fast: 'fast', default: 'default', complex: 'complex', local: 'local' }),
-        getLabel: (tier: string) => tier,
-      } as unknown as MessageRouterDeps['modelRouter'],
-      systemPrompt: 'test prompt',
-      toolRegistry: {
-        clone() { return this; },
-        register: vi.fn(),
-      } as unknown as MessageRouterDeps['toolRegistry'],
-      toolExecutor: {} as unknown as MessageRouterDeps['toolExecutor'],
-      config: {
-        agents: {
-          primary_tier: 'default',
-          delegation: {
-            compaction: 'fast',
-            memory_extraction: 'fast',
-            classification: 'fast',
-            tool_summarisation: 'fast',
-            complex_reasoning: 'complex',
-          },
-          max_delegation_depth: 3,
-          max_iterations: 10,
-          auto_escalate: false,
-        },
-        compaction: { enabled: false },
-        models: { default: { provider: 'anthropic', model: 'claude' } },
-      } as unknown as MessageRouterDeps['config'],
-      externalBackends: {
-        codex: codexBackend,
-        gemini: geminiBackend,
-      } as unknown as MessageRouterDeps['externalBackends'],
-      defaultExternalBackendName: 'codex',
-    });
-
-    const reply = vi.fn(async (_message: OutboundMessage) => {});
-    await router.handler({
-      id: 'm-external-failover',
-      channel: 'telegram',
-      senderId: 'external-failover',
-      text: 'hello failover',
-      timestamp: Date.now(),
-    } as MessageRouterInput, reply);
-
-    expect(codexBackend.process).toHaveBeenCalled();
-    expect(geminiBackend.process).toHaveBeenCalled();
-    expect(processSpy).not.toHaveBeenCalled();
-    expect(reply).toHaveBeenCalledWith(expect.objectContaining({ text: 'gemini recovered' }));
-  });
-
-  it('uses per-agent backend override instead of default external backend', async () => {
-    const processSpy = vi.spyOn(AgentOrchestrator.prototype, 'process');
-    const session = {
-      id: 'telegram:agent-backend-override',
-      addMessage: vi.fn(),
-      getHistory: vi.fn(() => []),
-      clear: vi.fn(),
-      replaceHistory: vi.fn(),
-      getConfig: vi.fn(() => undefined),
-      setConfig: vi.fn(),
-      deleteConfig: vi.fn(),
-    };
-
-    const codexBackend = {
-      name: 'codex',
-      process: vi.fn(async () => 'codex response'),
-    };
-    const geminiBackend = {
-      name: 'gemini',
-      process: vi.fn(async () => 'gemini response'),
-    };
-
-    const agentConfigRegistry = new AgentConfigRegistry();
-    agentConfigRegistry.loadFromConfig({
-      coder: {
-        model_tier: 'complex',
-        backend: 'gemini',
-        sandbox: false,
-      },
-    });
-    const agentRouter = new AgentRouter({
-      channels: { telegram: 'coder' },
-      senders: {},
-    });
-
-    const router = createMessageRouter({
-      sessionManager: {
-        getSession: vi.fn(() => session),
-      } as unknown as MessageRouterDeps['sessionManager'],
-      modelRouter: {
-        getAvailableTiers: () => ['fast', 'default', 'complex', 'local'],
-        getAllLabels: () => ({ fast: 'fast', default: 'default', complex: 'complex', local: 'local' }),
-        getLabel: (tier: string) => tier,
-      } as unknown as MessageRouterDeps['modelRouter'],
-      systemPrompt: 'test prompt',
-      toolRegistry: {
-        clone() { return this; },
-        register: vi.fn(),
-      } as unknown as MessageRouterDeps['toolRegistry'],
-      toolExecutor: {} as unknown as MessageRouterDeps['toolExecutor'],
-      config: {
-        agents: {
-          primary_tier: 'default',
-          delegation: {
-            compaction: 'fast',
-            memory_extraction: 'fast',
-            classification: 'fast',
-            tool_summarisation: 'fast',
-            complex_reasoning: 'complex',
-          },
-          max_delegation_depth: 3,
-          max_iterations: 10,
-          auto_escalate: false,
-        },
-        compaction: { enabled: false },
-        models: { default: { provider: 'anthropic', model: 'claude' } },
-      } as unknown as MessageRouterDeps['config'],
-      agentConfigRegistry,
-      agentRouter,
-      externalBackends: {
-        codex: codexBackend,
-        gemini: geminiBackend,
-      } as unknown as MessageRouterDeps['externalBackends'],
-      defaultExternalBackendName: 'codex',
-    });
-
-    const reply = vi.fn(async (_message: OutboundMessage) => {});
-    await router.handler({
-      id: 'm-agent-backend-override',
-      channel: 'telegram',
-      senderId: 'user-agent-override',
-      text: 'route to gemini backend',
-      timestamp: Date.now(),
-    } as MessageRouterInput, reply);
-
-    expect(geminiBackend.process).toHaveBeenCalled();
-    expect(codexBackend.process).not.toHaveBeenCalled();
-    expect(processSpy).not.toHaveBeenCalled();
-    expect(reply).toHaveBeenCalledWith(expect.objectContaining({ text: 'gemini response' }));
-  });
-
-  it('falls back to native when per-agent backend is configured but unavailable', async () => {
-    const processSpy = vi.spyOn(AgentOrchestrator.prototype, 'process')
-      .mockResolvedValue('native response (missing backend)');
-    const session = {
-      id: 'telegram:missing-agent-backend',
-      addMessage: vi.fn(),
-      getHistory: vi.fn(() => []),
-      clear: vi.fn(),
-      replaceHistory: vi.fn(),
-      getConfig: vi.fn(() => undefined),
-      setConfig: vi.fn(),
-      deleteConfig: vi.fn(),
-    };
-
-    const agentConfigRegistry = new AgentConfigRegistry();
-    agentConfigRegistry.loadFromConfig({
-      coder: {
-        model_tier: 'complex',
-        backend: 'gemini',
-        sandbox: false,
-      },
-    });
-    const agentRouter = new AgentRouter({
-      channels: { telegram: 'coder' },
-      senders: {},
-    });
-
-    const codexBackend = {
-      name: 'codex',
-      process: vi.fn(async () => 'codex response'),
-    };
-
-    const router = createMessageRouter({
-      sessionManager: {
-        getSession: vi.fn(() => session),
-      } as unknown as MessageRouterDeps['sessionManager'],
-      modelRouter: {
-        getAvailableTiers: () => ['fast', 'default', 'complex', 'local'],
-        getAllLabels: () => ({ fast: 'fast', default: 'default', complex: 'complex', local: 'local' }),
-        getLabel: (tier: string) => tier,
-      } as unknown as MessageRouterDeps['modelRouter'],
-      systemPrompt: 'test prompt',
-      toolRegistry: {
-        clone() { return this; },
-        register: vi.fn(),
-      } as unknown as MessageRouterDeps['toolRegistry'],
-      toolExecutor: {} as unknown as MessageRouterDeps['toolExecutor'],
-      config: {
-        agents: {
-          primary_tier: 'default',
-          delegation: {
-            compaction: 'fast',
-            memory_extraction: 'fast',
-            classification: 'fast',
-            tool_summarisation: 'fast',
-            complex_reasoning: 'complex',
-          },
-          max_delegation_depth: 3,
-          max_iterations: 10,
-          auto_escalate: false,
-        },
-        compaction: { enabled: false },
-        models: { default: { provider: 'anthropic', model: 'claude' } },
-      } as unknown as MessageRouterDeps['config'],
-      agentConfigRegistry,
-      agentRouter,
-      externalBackends: {
-        codex: codexBackend,
-      } as unknown as MessageRouterDeps['externalBackends'],
-      defaultExternalBackendName: 'codex',
-    });
-
-    const reply = vi.fn(async (_message: OutboundMessage) => {});
-    await router.handler({
-      id: 'm-missing-agent-backend',
-      channel: 'telegram',
-      senderId: 'user-missing-backend',
-      text: 'fall back to native',
-      timestamp: Date.now(),
-    } as MessageRouterInput, reply);
-
-    expect(codexBackend.process).not.toHaveBeenCalled();
-    expect(processSpy).toHaveBeenCalled();
-    expect(reply).toHaveBeenCalledWith(expect.objectContaining({ text: 'native response (missing backend)' }));
-  });
 });
 
 describe('daemon talk mode (voice wake) integration', () => {