feat(browser): add local handoff presentation

src/app/background/index.ts

@@ -64,6 +64,7 @@ import { handleCookieRequest } from './handlers/cookies';
 import { handleUserAgentRequest } from './handlers/user-agent';
 import { handleRecordingRequest } from './handlers/recording';
 import { handleTransformRequest } from './handlers/transform';
+import { resolveHandoff } from '@/features/handoff/service';
 
 function originOf(url: string): string {
   const parsed = new URL(url);
@@ -299,21 +300,7 @@ async function handleRequest(request: ExtensionRequest, sender: Browser.runtime.
     }
     case 'handoff.resolve': {
       const input = request.payload;
-      const state = await updateState((current) => {
-        if (!current.handoff || current.handoff.id !== input.id || current.handoff.state !== 'waiting_for_user') {
-          throw new ExtensionError('handoff_not_waiting', '人工接管请求不存在或已经结束');
-        }
-        return {
-          ...current,
-          handoff: { ...current.handoff, state: input.outcome, resolvedAt: Date.now() },
-        };
-      });
-      const handoff = state.handoff!;
-      await setAgentRuntimeState(
-        input.outcome === 'completed' ? 'running' : 'paused',
-        await browserInstanceAccess('browser.tabs.read'),
-      );
-      await browser.action.setBadgeText({ text: '', tabId: handoff.target.tabId });
+      const { state, handoff } = await resolveHandoff(input.id, input.outcome);
       engineBridge.emitEvent('browser.handoff.changed', handoff);
       void appendAuditEvent({
         category: 'handoff', action: `handoff.${input.outcome}`, outcome: input.outcome === 'completed' ? 'success' : 'cancelled',

src/features/engine-bridge/service.test.ts

@@ -87,9 +87,26 @@ vi.mock('@/platform/storage/state', () => ({
 
 vi.mock('@/protocol/capabilities', () => ({
   BRIDGE_CAPABILITIES: [],
+  capabilityVisibleToAgent: vi.fn((method: string) => ![
+    'browser.thumbnail',
+    'browser.handoff.presentation.get',
+    'browser.handoff.focus',
+    'browser.handoff.resolve',
+  ].includes(method)),
   getBridgeCapabilityCatalog: vi.fn(async () => ({ version: 1, capabilities: [] })),
 }));
 
+vi.mock('@/features/grants/capability-context', () => ({
+  browserInstanceAccess: vi.fn(async () => ({
+    id: 'paired-browser-instance',
+    taskId: 'paired-browser-instance',
+    targets: [],
+    scopes: ['browser.tabs.read'],
+    createdAt: 0,
+    expiresAt: Number.MAX_SAFE_INTEGER,
+  })),
+}));
+
 vi.mock('@/features/grants/service', () => ({
   routeCapability: vi.fn(async () => ({ ok: true })),
 }));
@@ -129,6 +146,7 @@ import {
   BRIDGE_HEARTBEAT_TIMEOUT_MS,
   EngineBridge,
 } from './service';
+import { beginAgentAction } from '@/features/agent-runtime/service';
 import {
   BRIDGE_CHUNK_TIMEOUT_MS,
   BRIDGE_PROTOCOL_VERSION,
@@ -214,6 +232,26 @@ describe('Engine Bridge transport lifecycle', () => {
     expect(socket.readyState).toBe(FakeWebSocket.CLOSED);
   });
 
+  it('routes local UI capabilities without entering the paused Agent action gate', async () => {
+    const bridge = new EngineBridge();
+    const socket = await connect(bridge);
+
+    socket.receive({
+      type: 'request',
+      id: 'local-ui-1',
+      method: 'browser.handoff.presentation.get',
+      params: { handoffId: 'handoff-1' },
+    });
+    await vi.advanceTimersByTimeAsync(0);
+
+    expect(socket.sent.map((item) => JSON.parse(item)).find((item) => item.id === 'local-ui-1')).toMatchObject({
+      type: 'response',
+      id: 'local-ui-1',
+      result: { ok: true },
+    });
+    expect(beginAgentAction).not.toHaveBeenCalled();
+  });
+
   it('closes a half-open connection and rejects pending calls after missed heartbeats', async () => {
     const bridge = new EngineBridge();
     const socket = await connect(bridge);

src/features/engine-bridge/service.ts

@@ -1,7 +1,11 @@
 import { browser } from 'wxt/browser';
 import type { BridgeEnvelope } from '@/types/messages';
 import type { BridgeConfig, BridgePairingStatus, BridgePublicKey, BridgeStatus } from '@/types/models';
-import { BRIDGE_CAPABILITIES, getBridgeCapabilityCatalog } from '@/protocol/capabilities';
+import {
+  BRIDGE_CAPABILITIES,
+  capabilityVisibleToAgent,
+  getBridgeCapabilityCatalog,
+} from '@/protocol/capabilities';
 import {
   BRIDGE_CHUNK_BYTES, BRIDGE_CHUNK_THRESHOLD_BYTES, BRIDGE_CHUNK_TIMEOUT_MS,
   BRIDGE_MAX_CHUNK_TRANSFERS, BRIDGE_MAX_MESSAGE_BYTES, BRIDGE_PROTOCOL_VERSION, parseBridgeEnvelope,
@@ -525,11 +529,13 @@ export class EngineBridge {
     try {
       const grant = await browserInstanceAccess('browser.tabs.read');
       taskId = grant.taskId;
+      if (capabilityVisibleToAgent(message.method)) {
         actionId = (await beginAgentAction(grant, {
           requestId: message.id,
           method: message.method,
           targetTabId,
         })).id;
+      }
       const operation = routeCapability(message.method, message.params, (method, params) => this.requestEngine(method, params));
       const result = await Promise.race([operation, cancelled]);
       const durationMs = performance.now() - startedAt;

src/features/grants/capability-handlers/handoff.ts

@@ -2,16 +2,29 @@ import { browser } from 'wxt/browser';
 import type { HandoffReason } from '@/types/models';
 import type { CapabilityDomainHandler } from '../capability-context';
 import { allowedTarget } from '../capability-context';
-import { activateTab } from '@/platform/browser/targets';
 import { getTab } from '@/platform/browser/targets';
 import { getState, updateState } from '@/platform/storage/state';
 import { setAgentRuntimeState } from '@/features/agent-runtime/service';
 import { ExtensionError } from '@/shared/errors';
 import { HANDOFF_CAPABILITY_DOMAIN } from '../capability-domains';
+import { focusHandoff, getHandoffPresentation, resolveHandoff } from '@/features/handoff/service';
 
 export const handoffCapabilityHandler: CapabilityDomainHandler = {
   ...HANDOFF_CAPABILITY_DOMAIN,
   async handle({ method, input, grant }) {
+    if (method === 'browser.handoff.presentation.get') {
+      return getHandoffPresentation(String(input.handoffId || ''), grant);
+    }
+    if (method === 'browser.handoff.focus') {
+      return focusHandoff(String(input.handoffId || ''), grant);
+    }
+    if (method === 'browser.handoff.resolve') {
+      return resolveHandoff(
+        String(input.handoffId || ''),
+        input.outcome === 'cancelled' ? 'cancelled' : 'completed',
+        grant,
+      );
+    }
     if (method === 'browser.handoff.status') {
       const handoff = (await getState()).handoff;
       return handoff?.taskId === grant.taskId ? handoff : { state: 'idle' };
@@ -50,7 +63,6 @@ export const handoffCapabilityHandler: CapabilityDomainHandler = {
         },
       };
     });
-    await activateTab(resolvedTarget.tabId);
     await browser.action.setBadgeBackgroundColor({ color: '#ee7815' });
     await browser.action.setBadgeText({ text: '待确认', tabId: resolvedTarget.tabId });
     await setAgentRuntimeState('waiting_for_human', grant);

src/features/grants/capability-handlers/page.ts

@@ -14,6 +14,7 @@ import { listCookies } from '@/features/cookies/service';
 import { resolveTabCookieStoreId } from '@/platform/browser/isolation';
 import { ExtensionError } from '@/shared/errors';
 import { PAGE_CAPABILITY_DOMAIN } from '../capability-domains';
+import { getState } from '@/platform/storage/state';
 
 export const pageCapabilityHandler: CapabilityDomainHandler = {
   ...PAGE_CAPABILITY_DOMAIN,
@@ -63,7 +64,12 @@ export const pageCapabilityHandler: CapabilityDomainHandler = {
       await browser.action.setBadgeBackgroundColor({ color: '#f28c28' });
       await browser.action.setBadgeText({ text: '接管', tabId: target.tabId });
       globalThis.setTimeout(
-        () => void browser.action.setBadgeText({ text: '', tabId: target.tabId }),
+        () => void getState()
+          .then((state) => browser.action.setBadgeText({
+            text: state.bridge.managedInstance?.badge || '',
+            tabId: target.tabId,
+          }))
+          .catch(() => undefined),
         10_000,
       );
       return { activated: true, target };

src/features/handoff/service.test.ts

@@ -0,0 +1,110 @@
+import { beforeEach, describe, expect, it, vi } from 'vitest';
+
+const fixture = vi.hoisted(() => ({
+  state: {} as Record<string, unknown>,
+  activateTab: vi.fn(async () => undefined),
+  getFrame: vi.fn(),
+  getTab: vi.fn(),
+  resolveDocumentTarget: vi.fn(),
+  executeScript: vi.fn(),
+  scriptingTarget: vi.fn((target) => target),
+}));
+
+vi.mock('wxt/browser', () => ({
+  browser: {
+    storage: {},
+    webNavigation: { getFrame: fixture.getFrame },
+    scripting: { executeScript: fixture.executeScript },
+  },
+}));
+vi.mock('@/platform/storage/state', () => ({
+  getState: vi.fn(async () => structuredClone(fixture.state)),
+  updateState: vi.fn(),
+}));
+vi.mock('@/platform/browser/targets', () => ({
+  activateTab: fixture.activateTab,
+  getTab: fixture.getTab,
+  resolveDocumentTarget: fixture.resolveDocumentTarget,
+  scriptingTarget: fixture.scriptingTarget,
+}));
+
+import { ExtensionError } from '@/shared/errors';
+import { focusHandoff, getHandoffPresentation, isSafeHandoffPresentationDataUrl } from './service';
+
+const grant = {
+  id: 'paired-browser-instance',
+  taskId: 'paired-browser-instance',
+  targets: [],
+  scopes: [],
+  createdAt: 0,
+  expiresAt: Number.MAX_SAFE_INTEGER,
+};
+
+function waitingHandoff(origin = 'https://passport.example.test') {
+  return {
+    handoff: {
+      id: 'handoff-1',
+      taskId: 'paired-browser-instance',
+      state: 'waiting_for_user',
+      reason: 'qr_code',
+      target: {
+        tabId: 7,
+        frameId: 0,
+        documentId: 'document-old',
+        origin,
+        grantedUrl: `${origin}/login`,
+        title: 'Sign in',
+      },
+    },
+  };
+}
+
+describe('handoff presentation data URL validation', () => {
+  beforeEach(() => {
+    vi.clearAllMocks();
+    fixture.state = {};
+  });
+
+  it('accepts bounded raster data and rejects executable or oversized content', () => {
+    expect(isSafeHandoffPresentationDataUrl('data:image/png;base64,AAAA')).toBe(true);
+    expect(isSafeHandoffPresentationDataUrl('data:image/svg+xml,<svg onload="alert(1)"/>')).toBe(false);
+    expect(isSafeHandoffPresentationDataUrl(`data:image/png;base64,${'AAAA'.repeat(350_000)}`)).toBe(false);
+  });
+
+  it('focuses only the waiting handoff owned by the local paired task', async () => {
+    fixture.state = {
+      handoff: {
+        id: 'handoff-1',
+        taskId: 'paired-browser-instance',
+        state: 'waiting_for_user',
+        target: { tabId: 7 },
+      },
+    };
+
+    await expect(focusHandoff('handoff-1', grant)).resolves.toEqual({ focused: true, tabId: 7 });
+    expect(fixture.activateTab).toHaveBeenCalledWith(7);
+    await expect(focusHandoff('other-handoff', grant)).rejects.toMatchObject({ code: 'handoff_not_waiting' });
+  });
+
+  it('rebinds presentation reads after a same-origin document refresh', async () => {
+    fixture.state = waitingHandoff();
+    fixture.resolveDocumentTarget
+      .mockRejectedValueOnce(new ExtensionError('stale_document', 'stale'))
+      .mockResolvedValueOnce({ tabId: 7, frameId: 0, documentId: 'document-new' });
+    fixture.getFrame.mockResolvedValue({ url: 'https://passport.example.test/login?refreshed=1' });
+    fixture.getTab.mockResolvedValue({ id: 7 });
+    fixture.executeScript.mockResolvedValue([]);
+
+    await expect(getHandoffPresentation('handoff-1', grant)).resolves.toMatchObject({ state: 'not_found' });
+    expect(fixture.resolveDocumentTarget).toHaveBeenLastCalledWith({ tabId: 7, frameId: 0 });
+  });
+
+  it('reports a changed page instead of leaking a stale-document error', async () => {
+    fixture.state = waitingHandoff();
+    fixture.resolveDocumentTarget.mockRejectedValueOnce(new ExtensionError('stale_document', 'stale'));
+    fixture.getFrame.mockResolvedValue({ url: 'https://www.example.test/' });
+
+    await expect(getHandoffPresentation('handoff-1', grant)).resolves.toMatchObject({ state: 'page_changed' });
+    expect(fixture.resolveDocumentTarget).toHaveBeenCalledTimes(1);
+  });
+});

src/features/handoff/service.ts

@@ -0,0 +1,299 @@
+import { browser, type Browser } from 'wxt/browser';
+import { setAgentRuntimeState } from '@/features/agent-runtime/service';
+import { browserInstanceAccess } from '@/features/grants/capability-context';
+import { activateTab, getTab, resolveDocumentTarget, scriptingTarget } from '@/platform/browser/targets';
+import { getState, updateState } from '@/platform/storage/state';
+import { ExtensionError } from '@/shared/errors';
+import type { BridgeGrant, HandoffState, HumanHandoff } from '@/types/models';
+
+const MAX_PRESENTATION_BYTES = 1024 * 1024;
+const SAFE_RASTER_DATA_URL = /^data:image\/(?:png|jpeg|webp);base64,/i;
+
+interface PageQrCandidate {
+  dataUrl?: string;
+  source: 'image' | 'canvas' | 'svg' | 'background' | 'screenshot';
+  rect: { x: number; y: number; width: number; height: number };
+  viewport: { width: number; height: number; devicePixelRatio: number };
+  title: string;
+  url: string;
+}
+
+export interface HandoffPresentation {
+  handoffId: string;
+  state: HandoffState | 'not_found' | 'page_changed';
+  title: string;
+  url: string;
+  capturedAt: number;
+  source?: PageQrCandidate['source'];
+  dataUrl?: string;
+}
+
+async function resolvePresentationTarget(target: HumanHandoff['target']) {
+  try {
+    return await resolveDocumentTarget(target);
+  } catch (error) {
+    if (!(error instanceof ExtensionError) || !['stale_document', 'target_unavailable'].includes(error.code)) throw error;
+  }
+
+  const frame = await browser.webNavigation.getFrame({
+    tabId: target.tabId,
+    frameId: target.frameId,
+  }).catch(() => null);
+  if (!frame?.url || !/^https?:/i.test(frame.url) || new URL(frame.url).origin !== target.origin) return undefined;
+  return resolveDocumentTarget({ tabId: target.tabId, frameId: target.frameId }).catch(() => undefined);
+}
+
+function dataUrlBytes(value: string): number {
+  const comma = value.indexOf(',');
+  return comma < 0 ? Number.MAX_SAFE_INTEGER : Math.ceil((value.length - comma - 1) * 0.75);
+}
+
+export function isSafeHandoffPresentationDataUrl(value: unknown): value is string {
+  return typeof value === 'string'
+    && SAFE_RASTER_DATA_URL.test(value)
+    && dataUrlBytes(value) <= MAX_PRESENTATION_BYTES;
+}
+
+async function findQrCandidateInPage(): Promise<PageQrCandidate | undefined> {
+  const resolvePresentationDataUrl = async (source: string, width: number, height: number): Promise<string | undefined> => {
+    const rasterize = async (url: string): Promise<string | undefined> => {
+      const image = new Image();
+      image.decoding = 'async';
+      await new Promise<void>((resolve, reject) => {
+        image.onload = () => resolve();
+        image.onerror = () => reject(new Error('image load failed'));
+        image.src = url;
+      });
+      const canvas = document.createElement('canvas');
+      canvas.width = Math.min(1024, Math.max(1, image.naturalWidth || Math.round(width)));
+      canvas.height = Math.min(1024, Math.max(1, image.naturalHeight || Math.round(height)));
+      canvas.getContext('2d')?.drawImage(image, 0, 0, canvas.width, canvas.height);
+      return canvas.toDataURL('image/png');
+    };
+
+    try {
+      if (/^data:image\/(?:png|jpeg|webp);base64,/i.test(source)) return source;
+      if (/^data:image\/svg\+xml/i.test(source)) return rasterize(source);
+      if (!/^(?:blob:|https?:)/i.test(source)) return undefined;
+      const response = await fetch(source);
+      if (!response.ok) return undefined;
+      const blob = await response.blob();
+      if (blob.size > 1024 * 1024) return undefined;
+      const localUrl = URL.createObjectURL(blob);
+      try {
+        if (/^image\/(?:png|jpeg|webp)$/i.test(blob.type)) {
+          return await new Promise<string>((resolve, reject) => {
+            const reader = new FileReader();
+            reader.onload = () => resolve(String(reader.result || ''));
+            reader.onerror = () => reject(reader.error);
+            reader.readAsDataURL(blob);
+          });
+        }
+        if (blob.type === 'image/svg+xml') return await rasterize(localUrl);
+      } finally {
+        URL.revokeObjectURL(localUrl);
+      }
+    } catch {
+      return undefined;
+    }
+    return undefined;
+  };
+
+  const keywords = /(?:^|[^a-z])(qr|qrcode|scan)(?:[^a-z]|$)|二维码|扫码|扫码登录/i;
+  const selector = 'img,canvas,svg,[role="img"],[class*="qr" i],[id*="qr" i]';
+  const seen = new Set<Element>();
+  const candidates: Array<{ element: Element; score: number; rect: DOMRect }> = [];
+
+  for (const element of document.querySelectorAll(selector)) {
+    if (seen.has(element)) continue;
+    seen.add(element);
+    const rect = element.getBoundingClientRect();
+    const style = getComputedStyle(element);
+    if (
+      rect.width < 96 || rect.height < 96
+      || rect.bottom <= 0 || rect.right <= 0
+      || rect.top >= innerHeight || rect.left >= innerWidth
+      || style.display === 'none' || style.visibility === 'hidden' || Number(style.opacity) === 0
+    ) continue;
+    const ratio = rect.width / rect.height;
+    if (ratio < 0.72 || ratio > 1.38) continue;
+
+    const ownText = [
+      element.id,
+      element.getAttribute('class'),
+      element.getAttribute('alt'),
+      element.getAttribute('aria-label'),
+      element.getAttribute('title'),
+    ].filter(Boolean).join(' ');
+    let contextText = '';
+    let parent: Element | null = element;
+    for (let depth = 0; parent && depth < 4; depth += 1, parent = parent.parentElement) {
+      contextText += ` ${parent.textContent || ''}`;
+      if (contextText.length >= 500) break;
+    }
+    const inDialog = Boolean(element.closest('dialog,[role="dialog"],[aria-modal="true"]'));
+    const score = (keywords.test(ownText) ? 8 : 0)
+      + (keywords.test(contextText.slice(0, 500)) ? 5 : 0)
+      + (Math.abs(1 - ratio) < 0.12 ? 4 : 2)
+      + (inDialog ? 2 : 0)
+      + (element instanceof HTMLCanvasElement || element instanceof SVGElement ? 1 : 0);
+    if (score >= 6) candidates.push({ element, score, rect });
+  }
+
+  candidates.sort((left, right) => right.score - left.score || right.rect.width - left.rect.width);
+  for (const { element, rect } of candidates.slice(0, 8)) {
+    let source: PageQrCandidate['source'] = 'screenshot';
+    let dataUrl: string | undefined;
+    try {
+      if (element instanceof HTMLCanvasElement) {
+        source = 'canvas';
+        dataUrl = element.toDataURL('image/png');
+      } else if (element instanceof SVGElement) {
+        source = 'svg';
+        const svg = new XMLSerializer().serializeToString(element);
+        dataUrl = await resolvePresentationDataUrl(
+          `data:image/svg+xml;charset=utf-8,${encodeURIComponent(svg)}`,
+          rect.width,
+          rect.height,
+        );
+      } else {
+        const imageSource = element instanceof HTMLImageElement
+          ? element.currentSrc || element.src
+          : getComputedStyle(element).backgroundImage.match(/^url\(["']?(.*?)["']?\)$/)?.[1] || '';
+        source = element instanceof HTMLImageElement ? 'image' : 'background';
+        dataUrl = await resolvePresentationDataUrl(imageSource, rect.width, rect.height);
+      }
+    } catch {
+      dataUrl = undefined;
+    }
+    return {
+      dataUrl,
+      source: dataUrl ? source : 'screenshot',
+      rect: { x: rect.x, y: rect.y, width: rect.width, height: rect.height },
+      viewport: { width: innerWidth, height: innerHeight, devicePixelRatio: devicePixelRatio || 1 },
+      title: document.title,
+      url: location.href,
+    };
+  }
+  return undefined;
+}
+
+async function cropVisibleTab(
+  tab: Awaited<ReturnType<typeof getTab>>,
+  candidate: PageQrCandidate,
+): Promise<string | undefined> {
+  if (!tab.active || typeof OffscreenCanvas === 'undefined') return undefined;
+  const screenshot = await browser.tabs.captureVisibleTab(tab.windowId, { format: 'png' });
+  const bitmap = await createImageBitmap(await (await fetch(screenshot)).blob());
+  const scaleX = bitmap.width / candidate.viewport.width;
+  const scaleY = bitmap.height / candidate.viewport.height;
+  const padding = 12;
+  const x = Math.max(0, Math.floor((candidate.rect.x - padding) * scaleX));
+  const y = Math.max(0, Math.floor((candidate.rect.y - padding) * scaleY));
+  const width = Math.min(bitmap.width - x, Math.ceil((candidate.rect.width + padding * 2) * scaleX));
+  const height = Math.min(bitmap.height - y, Math.ceil((candidate.rect.height + padding * 2) * scaleY));
+  if (width < 1 || height < 1) return undefined;
+  const canvas = new OffscreenCanvas(width, height);
+  const context = canvas.getContext('2d');
+  if (!context) return undefined;
+  context.fillStyle = '#fff';
+  context.fillRect(0, 0, width, height);
+  context.drawImage(bitmap, x, y, width, height, 0, 0, width, height);
+  bitmap.close();
+  const bytes = new Uint8Array(await (await canvas.convertToBlob({ type: 'image/png' })).arrayBuffer());
+  if (bytes.byteLength > MAX_PRESENTATION_BYTES) return undefined;
+  let binary = '';
+  for (let offset = 0; offset < bytes.length; offset += 0x8000) {
+    binary += String.fromCharCode(...bytes.subarray(offset, offset + 0x8000));
+  }
+  return `data:image/png;base64,${btoa(binary)}`;
+}
+
+export async function getHandoffPresentation(handoffId: string, grant: BridgeGrant): Promise<HandoffPresentation> {
+  const handoff = (await getState()).handoff;
+  if (!handoff || handoff.id !== handoffId || handoff.taskId !== grant.taskId) {
+    throw new ExtensionError('handoff_not_found', '人工接管请求不存在');
+  }
+  const base = {
+    handoffId,
+    state: handoff.state,
+    title: handoff.target.title || '',
+    url: handoff.target.grantedUrl || '',
+    capturedAt: Date.now(),
+  };
+  if (handoff.state !== 'waiting_for_user' || handoff.reason !== 'qr_code') return base;
+
+  const target = await resolvePresentationTarget(handoff.target);
+  if (!target) return { ...base, state: 'page_changed' };
+  const tab = await getTab(target.tabId);
+  const results = await browser.scripting.executeScript({
+    target: scriptingTarget(target),
+    world: 'MAIN',
+    func: findQrCandidateInPage,
+  }) as Array<Browser.scripting.InjectionResult<PageQrCandidate | undefined>>;
+  if (results.length !== 1 || !results[0]?.result) return { ...base, state: 'not_found' };
+
+  const candidate = results[0].result;
+  const directDataUrl = isSafeHandoffPresentationDataUrl(candidate.dataUrl) ? candidate.dataUrl : undefined;
+  const dataUrl = directDataUrl
+    ? directDataUrl
+    : target.frameId === 0
+      ? await cropVisibleTab(tab, candidate).catch(() => undefined)
+      : undefined;
+  if (!isSafeHandoffPresentationDataUrl(dataUrl)) {
+    return { ...base, state: 'not_found', title: candidate.title || base.title, url: candidate.url || base.url };
+  }
+  return {
+    ...base,
+    state: 'waiting_for_user',
+    title: candidate.title || base.title,
+    url: candidate.url || base.url,
+    source: directDataUrl ? candidate.source : 'screenshot',
+    dataUrl,
+  };
+}
+
+export async function focusHandoff(handoffId: string, grant: BridgeGrant): Promise<{ focused: true; tabId: number }> {
+  const handoff = (await getState()).handoff;
+  if (
+    !handoff
+    || handoff.id !== handoffId
+    || handoff.taskId !== grant.taskId
+    || handoff.state !== 'waiting_for_user'
+  ) {
+    throw new ExtensionError('handoff_not_waiting', '人工接管请求不存在或已经结束');
+  }
+  await activateTab(handoff.target.tabId);
+  return { focused: true, tabId: handoff.target.tabId };
+}
+
+export async function resolveHandoff(
+  handoffId: string,
+  outcome: Extract<HandoffState, 'completed' | 'cancelled'>,
+  grant?: BridgeGrant,
+): Promise<{ state: Awaited<ReturnType<typeof getState>>; handoff: HumanHandoff }> {
+  const state = await updateState((current) => {
+    if (
+      !current.handoff
+      || current.handoff.id !== handoffId
+      || current.handoff.state !== 'waiting_for_user'
+      || (grant && current.handoff.taskId !== grant.taskId)
+    ) {
+      throw new ExtensionError('handoff_not_waiting', '人工接管请求不存在或已经结束');
+    }
+    return {
+      ...current,
+      handoff: { ...current.handoff, state: outcome, resolvedAt: Date.now() },
+    };
+  });
+  const handoff = state.handoff!;
+  await setAgentRuntimeState(
+    outcome === 'completed' ? 'running' : 'paused',
+    grant || await browserInstanceAccess('browser.tabs.read'),
+  );
+  await browser.action.setBadgeText({
+    text: state.bridge.managedInstance?.badge || '',
+    tabId: handoff.target.tabId,
+  }).catch(() => undefined);
+  return { state, handoff };
+}

src/protocol/bridge.ts

@@ -193,6 +193,16 @@ export const capabilityParams = {
     message: v.optional(v.pipe(v.string(), v.trim(), v.maxLength(500)), ''),
   }),
   'browser.handoff.status': v.optional(v.strictObject({})),
+  'browser.handoff.presentation.get': v.strictObject({
+    handoffId: id,
+  }),
+  'browser.handoff.focus': v.strictObject({
+    handoffId: id,
+  }),
+  'browser.handoff.resolve': v.strictObject({
+    handoffId: id,
+    outcome: v.picklist(['completed', 'cancelled']),
+  }),
   'browser.network.start': v.optional(v.strictObject({
     ...targetFields,
     captureHeaders: v.optional(v.boolean()),

src/protocol/capabilities.test.ts

@@ -3,6 +3,7 @@ import {
   BRIDGE_CAPABILITIES,
   canonicalCapabilityCatalogPayload,
   capabilityBaseScope,
+  capabilityVisibleToAgent,
   getBridgeCapabilityCatalog,
 } from './capabilities';
 
@@ -34,6 +35,23 @@ describe('versioned Bridge capability catalog', () => {
     expect(JSON.stringify(evalCapability?.paramsSchema)).toContain('"mode"');
     expect(JSON.stringify(evalCapability?.paramsSchema)).toContain('"program"');
     expect(capabilityBaseScope('browser.profile.validate')).toBe('browser.transform.execute');
+    expect(catalog.capabilities.find((capability) => capability.method === 'browser.thumbnail')).toMatchObject({
+      agentVisible: false,
+    });
+    expect(catalog.capabilities.find((capability) => capability.method === 'browser.handoff.presentation.get')).toMatchObject({
+      agentVisible: false,
+    });
+    expect(catalog.capabilities.find((capability) => capability.method === 'browser.handoff.focus')).toMatchObject({
+      agentVisible: false,
+    });
+    expect(catalog.capabilities.find((capability) => capability.method === 'browser.handoff.resolve')).toMatchObject({
+      agentVisible: false,
+    });
+    expect(capabilityVisibleToAgent('browser.handoff.presentation.get')).toBe(false);
+    expect(capabilityVisibleToAgent('browser.handoff.focus')).toBe(false);
+    expect(capabilityVisibleToAgent('browser.handoff.resolve')).toBe(false);
+    expect(capabilityVisibleToAgent('browser.thumbnail')).toBe(false);
+    expect(capabilityVisibleToAgent('browser.context')).toBe(true);
     expect(catalog.capabilities.find((capability) => capability.method === 'browser.transform.recovery.capture')).toMatchObject({
       access: 'dangerous',
       scopes: ['browser.transform.manage', 'browser.debugger.control', 'browser.callable.execute'],

src/protocol/capabilities.ts

@@ -20,6 +20,7 @@ export type BridgeCapabilityMethod = keyof typeof capabilityParams;
 interface CapabilityMetadata {
   domain: BridgeCapabilityDomain;
   access: BridgeCapabilityAccess;
+  agentVisible?: boolean;
   summary: string;
   scopes: CapabilityScope[];
   conditionalScopes?: BridgeCapabilityScopeCondition[];
@@ -42,7 +43,7 @@ const CAPABILITY_METADATA = {
   },
   'browser.thumbnail': {
     domain: 'page', access: 'read', summary: '读取当前可见标签页的低清预览图，供 Yakit 实例列表展示',
-    scopes: ['browser.tabs.read'], targetMode: 'tab', defaultTimeoutMs: READ_TIMEOUT_MS,
+    scopes: ['browser.tabs.read'], targetMode: 'tab', defaultTimeoutMs: READ_TIMEOUT_MS, agentVisible: false,
   },
   'browser.isolation.inspect': {
     domain: 'isolation', access: 'read', summary: '读取浏览器实例内标签页的 Cookie Store 与身份隔离上下文',
@@ -168,13 +169,29 @@ const CAPABILITY_METADATA = {
     scopes: ['browser.instance.close'], targetMode: 'none', defaultTimeoutMs: READ_TIMEOUT_MS,
   },
   'browser.handoff.request': {
-    domain: 'handoff', access: 'write', summary: '请求用户完成扫码、MFA、验证码或设备确认',
+    domain: 'handoff', access: 'write',
+    summary: '页面需要用户扫码、MFA、验证码或设备确认时调用；Yakit 会在本地呈现交互内容，Agent 只等待结果',
     scopes: ['browser.human.takeover'], targetMode: 'document', defaultTimeoutMs: READ_TIMEOUT_MS,
   },
   'browser.handoff.status': {
     domain: 'handoff', access: 'read', summary: '读取当前人工接管状态',
     scopes: ['browser.human.takeover'], targetMode: 'none', defaultTimeoutMs: READ_TIMEOUT_MS,
   },
+  'browser.handoff.presentation.get': {
+    domain: 'handoff', access: 'sensitive-read', agentVisible: false,
+    summary: '仅在本机提取当前扫码接管的二维码展示数据',
+    scopes: ['browser.human.takeover'], targetMode: 'none', defaultTimeoutMs: READ_TIMEOUT_MS,
+  },
+  'browser.handoff.focus': {
+    domain: 'handoff', access: 'write', agentVisible: false,
+    summary: '二维码无法在本地呈现时，由 Yakit 将对应浏览器实例切换到前台',
+    scopes: ['browser.human.takeover'], targetMode: 'none', defaultTimeoutMs: READ_TIMEOUT_MS,
+  },
+  'browser.handoff.resolve': {
+    domain: 'handoff', access: 'write', agentVisible: false,
+    summary: '由 Yakit 本地界面完成或取消人工接管',
+    scopes: ['browser.human.takeover'], targetMode: 'none', defaultTimeoutMs: READ_TIMEOUT_MS,
+  },
   'browser.network.start': {
     domain: 'network', access: 'control', summary: '启动有界网络捕获，可选采集请求头和 Body',
     scopes: ['browser.network.capture'],
@@ -458,6 +475,11 @@ export function capabilityBaseScope(method: string): CapabilityScope | undefined
   return CAPABILITY_METADATA[method as BridgeCapabilityMethod]?.scopes[0];
 }
 
+export function capabilityVisibleToAgent(method: string): boolean {
+  const metadata = CAPABILITY_METADATA[method as BridgeCapabilityMethod] as CapabilityMetadata | undefined;
+  return metadata?.agentVisible !== false;
+}
+
 export function isControlScopeSet(scopes: readonly CapabilityScope[]): boolean {
   return scopes.some((scope) => !READ_CAPABILITY_SCOPES.includes(scope));
 }

src/types/messages.ts

@@ -306,6 +306,8 @@ export interface BridgeCapabilityDescriptor {
   method: string;
   domain: BridgeCapabilityDomain;
   access: BridgeCapabilityAccess;
+  /** False keeps local presentation/control methods out of the Agent tool catalog. */
+  agentVisible?: boolean;
   summary: string;
   scopes: CapabilityScope[];
   conditionalScopes?: BridgeCapabilityScopeCondition[];