chore: fix CI + release 0.5.0

[triuzzi]

Summary

Fixes all blocking CI failures and bumps to 0.5.0.

CI fixes

• `run-tests.yml`: install Brave Browser before running e2e tests on ubuntu/macos/windows. The chrome-devtools test suite `runCli(['start'])` spawns Brave; runners come with Chrome pre-installed but not Brave, so every e2e `list_pages`/`take_screenshot` test failed with "Could not find Brave Browser".
• `eslint.config.mjs` + `brave-integration.test.mjs`: add the integration test to `allowDefaultProject` (so the TS project service can parse it), rename unused `label`/`submitUid` to underscore-prefixed, and auto-format. Resolves the `[Required] Check correct format` blocker.
• `scripts/generate-cli.ts`: write the generated CLI to `brave-devtools-cli-options.ts` (was still chrome-named) and use `BRAVE_DEVTOOLS_MCP_NO_USAGE_STATISTICS` in the spawn env. Resolves the `[Required] Check docs updated` blocker (`npm run gen` would otherwise leave a stray chrome-named file).
• Remove `.github/workflows/release-please.yml`: it referenced `BROWSER_AUTOMATION_BOT_TOKEN`, an upstream-only secret. We cut releases manually via npm publish + git tag + gh release create, so this workflow is dead code in our fork.
• `npm run gen` regenerated: `brave-devtools-mcp-cli-options.ts`, `flag_usage_metrics.json`. Prettier reformatted: `check-latest-version.ts`, `src/browser.ts`, `README.md`, `brave-integration.test.html`.

Release

Bumps `package.json`, `package-lock.json`, `server.json` (top-level + `packages[0]`), `.claude-plugin/plugin.json`, `src/version.ts` to 0.5.0.

Test plan

• `npm run clean && npm run build` — clean
• `npm run check-format` — clean (eslint + prettier)
• `npm run gen` — no diff after re-run
• `node scripts/test.mjs` — all passing locally
• CI all green on this PR
• After merge: tag `v0.5.0`, GitHub release, `npm publish brave-mcp@0.5.0`

🤖 Generated with Claude Code