test: add browser extension QA harness

.gitignore

@@ -9,3 +9,10 @@
 
 # gstack local reports
 .gstack/
+
+# Playwright extension QA artifacts
+/node_modules/
+/playwright-report/
+/test-results/
+/blob-report/
+/.playwright/

AGENTS.md

@@ -28,6 +28,21 @@ Treat key material with care.
 - Test: `cargo test --workspace`.
 - Bump the git GPUI stack: `just bump-gpui` (the ONLY way to change those pins).
 
+## Branch hygiene — required before edits
+Before changing files, always establish the current branch and its source-of-truth status:
+
+1. Run `git status --short --branch`.
+2. If on `main`, run `git fetch origin --prune`, fast-forward from `origin/main`, then create a new
+   feature branch before editing.
+3. If not on `main`, run `git fetch origin --prune` and check whether the branch has already been
+   merged into current `origin/main`.
+   - If it has been merged, switch back to `main`, fast-forward from `origin/main`, and create a new
+     feature branch before editing.
+   - If it has not been merged, inspect the branch's upstream/ahead/behind state and update local
+     state before editing. Do not stack unrelated work on a stale or merged branch.
+4. If there are uncommitted changes, identify whether they are user changes before switching,
+   rebasing, stashing, or applying patches.
+
 ## Definition of done (all must hold; show command output as evidence)
 1. `cargo fmt --all --check` clean
 2. `just check` green (both feature configs)

CLAUDE.md

@@ -32,6 +32,22 @@ before you're done. (For UI work you must build the app: `just check`.)
 4. No new or changed dependencies (`Cargo.toml` / `Cargo.lock`) unless explicitly approved
    (the git GPUI stack is bumped only via `just bump-gpui` — never hand-edit those pins)
 
+## Branch hygiene — required before edits
+
+Before changing files, always establish the current branch and its source-of-truth status:
+
+1. Run `git status --short --branch`.
+2. If on `main`, run `git fetch origin --prune`, fast-forward from `origin/main`, then create a new
+   feature branch before editing.
+3. If not on `main`, run `git fetch origin --prune` and check whether the branch has already been
+   merged into current `origin/main`.
+   - If it has been merged, switch back to `main`, fast-forward from `origin/main`, and create a new
+     feature branch before editing.
+   - If it has not been merged, inspect the branch's upstream/ahead/behind state and update local
+     state before editing. Do not stack unrelated work on a stale or merged branch.
+4. If there are uncommitted changes, identify whether they are user changes before switching,
+   rebasing, stashing, or applying patches.
+
 ## Code constraints
 
 **Enforced workspace-wide** by `[workspace.lints]` + `clippy.toml` (CI fails the build):

docs/browser-extension-qa.md

@@ -0,0 +1,89 @@
+# Browser extension QA
+
+Deckard's browser connector is a local-only, experimental extension. This QA harness is a
+small Playwright smoke suite, not a full end-to-end wallet test suite. It checks that the
+unpacked extension loads in Chromium, injects the EIP-1193 provider, and can connect the local
+test dapp through the Deckard browser bridge.
+
+The suite follows Playwright's Chrome extension guidance: extensions run in Chromium through a
+persistent browser context, loaded with `--disable-extensions-except` and `--load-extension`.
+Manifest V3 uses a service worker, so the extension id is derived from the service worker URL.
+
+## Install
+
+Install the Node dependencies:
+
+```sh
+npm install
+```
+
+Install Playwright's bundled Chromium:
+
+```sh
+npm run qa:browser:install
+```
+
+Use the bundled Playwright Chromium for this harness. Do not switch it to system Chrome or Edge;
+those browsers no longer support the extension sideload flags that this local QA path needs.
+
+## Run
+
+Run the extension smoke tests headless:
+
+```sh
+npm run qa:extension
+```
+
+Run headed while debugging:
+
+```sh
+npm run qa:extension:headed
+```
+
+The test starts `deckard-browser-bridge` in dev/mock mode on `127.0.0.1:8765`, serves
+`examples/browser-bridge-dapp` on `127.0.0.1:8777`, loads `extension/` unpacked, and verifies:
+
+- the Manifest V3 service worker loads
+- `window.ethereum` is injected into the local test dapp
+- `eth_accounts` returns `[]` before permission
+- `eth_requestAccounts` returns the deterministic dev/mock address
+- `eth_accounts` returns that address after permission
+- `eth_chainId` returns Sepolia (`0xaa36a7`)
+
+If you already have a compatible bridge running on `127.0.0.1:8765`, stop it before running the
+suite. To intentionally reuse it instead, set:
+
+```sh
+DECKARD_QA_REUSE_BRIDGE=1 npm run qa:extension
+```
+
+## Artifacts
+
+Generated artifacts are ignored by git:
+
+- `playwright-report/` — HTML reports
+- `test-results/` — screenshots, traces, and videos
+- `.playwright/` — persistent Chromium profiles
+- `blob-report/` — Playwright blob reports
+
+The passing dapp-connection test writes `connected-dapp.png` under `test-results/extension/...`.
+On failure, Playwright retains traces, screenshots, and videos according to
+`playwright.extension.config.ts`.
+
+## Security
+
+- Never use or commit a real seed phrase, private key, production wallet, browser profile, or
+  mainnet-funded account in this harness.
+- The checked-in test uses only a deterministic mock address:
+  `0xdeC0ded0000000000000000000000000000001193`.
+- The extension has no keys and performs no signing.
+- Keep transaction and signing flows out of this harness until Deckard has reviewed approval UI
+  and local-chain-only signing tests.
+- Do not log extension storage, browser profile contents, cookies, local storage, seeds, keys, or
+  wallet state.
+
+## Scope
+
+This suite proves the browser connector slice. It does not replace Rust unit/integration tests,
+the real daemon proof for `deckard-signerd`, or a future transaction/signature test suite on a
+local chain.

examples/browser-bridge-dapp/index.html

@@ -3,6 +3,7 @@
   <head>
     <meta charset="utf-8" />
     <meta name="viewport" content="width=device-width, initial-scale=1" />
+    <link rel="icon" href="data:," />
     <title>Deckard EIP-1193 bridge test dapp</title>
     <style>
       :root { color-scheme: dark; font-family: ui-monospace, SFMono-Regular, Menlo, monospace; }

package.json

@@ -0,0 +1,13 @@
+{
+  "name": "deckard",
+  "private": true,
+  "type": "module",
+  "scripts": {
+    "qa:browser:install": "playwright install chromium",
+    "qa:extension": "playwright test --config=playwright.extension.config.ts",
+    "qa:extension:headed": "playwright test --config=playwright.extension.config.ts --headed"
+  },
+  "devDependencies": {
+    "@playwright/test": "^1.61.0"
+  }
+}

playwright.extension.config.ts

@@ -0,0 +1,28 @@
+import { defineConfig } from '@playwright/test';
+
+export default defineConfig({
+  testDir: './tests/extension',
+  fullyParallel: false,
+  workers: 1,
+  timeout: 30_000,
+  reporter: [
+    ['list'],
+    ['html', { outputFolder: 'playwright-report/extension', open: 'never' }],
+  ],
+  outputDir: 'test-results/extension',
+  use: {
+    baseURL: 'http://127.0.0.1:8777',
+    screenshot: 'only-on-failure',
+    trace: 'retain-on-failure',
+    video: 'retain-on-failure',
+    serviceWorkers: 'allow',
+  },
+  webServer: {
+    command: 'python3 -m http.server 8777 --directory examples/browser-bridge-dapp',
+    url: 'http://127.0.0.1:8777',
+    reuseExistingServer: !process.env.CI,
+    stdout: 'pipe',
+    stderr: 'pipe',
+    timeout: 10_000,
+  },
+});

tests/extension/browser-bridge-extension.spec.ts

@@ -0,0 +1,76 @@
+import { test, expect } from './fixtures';
+
+const mockAccount = '0xdeC0ded0000000000000000000000000000001193';
+
+test('extension service worker loads', async ({ context, extensionId }) => {
+  const worker = context
+    .serviceWorkers()
+    .find((serviceWorker) => serviceWorker.url().startsWith(`chrome-extension://${extensionId}/`));
+
+  expect(extensionId).toMatch(/^[a-p]{32}$/);
+  expect(worker?.url()).toBe(`chrome-extension://${extensionId}/background.js`);
+});
+
+test('local dapp can connect through the injected provider', async ({ page }, testInfo) => {
+  const pageErrors: string[] = [];
+  page.on('pageerror', (error) => pageErrors.push(error.message));
+  page.on('console', (message) => {
+    if (message.type() === 'error') {
+      pageErrors.push(message.text());
+    }
+  });
+
+  await page.goto('/');
+  await expect(page.locator('#output')).toContainText('window.ethereum detected');
+
+  const providerState = await page.evaluate(async () => {
+    const provider = window.ethereum;
+    if (!provider) {
+      throw new Error('window.ethereum missing');
+    }
+    const accountsBefore = await provider.request({ method: 'eth_accounts' });
+    const requestAccounts = await provider.request({ method: 'eth_requestAccounts' });
+    const accountsAfter = await provider.request({ method: 'eth_accounts' });
+    const chainId = await provider.request({ method: 'eth_chainId' });
+    return {
+      accountsBefore,
+      requestAccounts,
+      accountsAfter,
+      chainId,
+      isDeckard: Boolean(provider.isDeckard),
+      selectedAddress: provider.selectedAddress,
+    };
+  });
+
+  expect(providerState).toEqual({
+    accountsBefore: [],
+    requestAccounts: [mockAccount],
+    accountsAfter: [mockAccount],
+    chainId: '0xaa36a7',
+    isDeckard: true,
+    selectedAddress: mockAccount,
+  });
+  expect(pageErrors).toEqual([]);
+
+  await page.evaluate((state) => {
+    const output = document.querySelector('#output');
+    if (output) {
+      output.textContent = JSON.stringify(state, null, 2);
+    }
+  }, providerState);
+
+  await page.screenshot({
+    path: testInfo.outputPath('connected-dapp.png'),
+    fullPage: true,
+  });
+});
+
+declare global {
+  interface Window {
+    ethereum?: {
+      isDeckard?: boolean;
+      selectedAddress?: string | null;
+      request(args: { method: string; params?: unknown[] }): Promise<unknown>;
+    };
+  }
+}