Verifying Web UI changes (Playwright + rich HTML report)

When you modify the Web UI (any Vue file under frontend/src/), verify it end-to-end with a Playwright sweep that captures screenshots and packages them into a self-contained HTML report. This is the same workflow used to verify Spec 046 v2 — see specs/046-local-first-onboarding/verification/ for a worked example.

The pattern, in order:

Stand up a fresh mcpproxy. Use a throwaway data-dir so persisted state doesn't bleed between runs:

bash

pkill -f 'mcpproxy serve.*<port>' 2>/dev/null; sleep 1
rm -rf /tmp/mcpproxy-uitest/{config.db,index.bleve,logs} 2>/dev/null
cat > /tmp/mcpproxy-uitest/mcp_config.json <<'EOF'
{ "listen": "127.0.0.1:18081", "data_dir": "/tmp/mcpproxy-uitest", "api_key": "uitest", "enable_web_ui": true, "enable_socket": false, "telemetry": {"enabled": false}, "mcpServers": [] }
EOF
./mcpproxy serve --config=/tmp/mcpproxy-uitest/mcp_config.json --listen=127.0.0.1:18081 --log-level=info > /tmp/mcpproxy-uitest/server.log 2>&1 &
until curl -sf -H "X-API-Key: uitest" http://127.0.0.1:18081/api/v1/status >/dev/null; do sleep 1; done

Reuse the existing Playwright install. e2e/playwright/node_modules already has Playwright + Chromium 1217. Symlink it into your scratch dir:
bash
```
mkdir -p /tmp/uitest && cd /tmp/uitest
ln -sfn /Users/user/repos/mcpproxy-go/e2e/playwright/node_modules ./node_modules
```

Pin the Chromium binary in playwright.config.ts so Playwright doesn't try to download a different version:

import { defineConfig } from '@playwright/test';
export default defineConfig({
  testDir: '.', timeout: 30000, fullyParallel: false, workers: 1, retries: 0,
  use: {
    headless: true,
    viewport: { width: 1440, height: 900 },
    launchOptions: {
      executablePath: '/Users/user/Library/Caches/ms-playwright/chromium-1217/chrome-mac-arm64/Google Chrome for Testing.app/Contents/MacOS/Google Chrome for Testing',
    },
  },
});

Write the spec. Use data-test attributes already on the components (the project convention). For new components, add them. Drive scenarios with page.locator('[data-test="..."]'). Always use page.waitForLoadState('domcontentloaded') — networkidle hangs because of the SSE channel. Snapshot each state with page.screenshot({ path: ... }). Number screenshots in execution order so the report renders left-to-right.
Run. ./node_modules/.bin/playwright test --reporter=list. Iterate until green.
Build the rich HTML report. A short Python script that base64-embeds each PNG and wraps it in a styled <details> per scenario produces a single self-contained HTML file the user can open offline. Pattern: top summary card with pass/fail counts, then one collapsible per scenario with Expected / Observed / inline screenshot. The reference implementation is /tmp/wizard-v2-verify/build-report.py from the v2 work — clone it and update the SCENARIOS list. Output goes to specs/<feature>/verification/report.html.
Drop screenshots + report alongside the spec. Always commit them with the spec changes — they're part of the trace.
Surface the report. End your reply with open <path-to-report.html> so the user can review without re-running the suite.

Key gotchas:

The wizard's <dialog> element renders as [open] only when the Vue store sets it. To assert open/closed state robustly, query the dialog property in page.evaluate(), not aria-hidden or styling.
The default config from a stub file does NOT trigger applyFirstRunDockerIsolation — that only runs when the config file is absent at boot. To test the "Docker auto-enabled" path, either let mcpproxy create the config or pre-set docker_isolation.enabled: true in your stub.
For browser-driven verification of subtle states (badge counts, empty/loaded transitions), prefer the Playwright spec over ad-hoc screenshots from the chrome-in-chrome MCP — the spec is reproducible and a CI agent can re-run it.