feat: Phase 1 foundation — config, webhooks, JUnit, tests (v0.5.0)

[drewstone]

Summary

• Config file system — agent-browser-driver.config.ts with defineConfig() for IDE autocomplete. loadConfig() searches up the directory tree, mergeConfig() does last-wins for scalars/arrays, concat for sinks only. CLI --config flag; all CLI flags override config values without clobbering unrelated config file settings.

• WebhookSink — ArtifactSink implementation that POSTs artifact metadata (and optionally base64 data) to any webhook URL. Event type filtering, custom headers, configurable max payload size, exponential backoff retry (1s/2s/4s). Never throws (infra-as-best-effort). close() accepts optional pass/fail summary.

• JUnit XML reporter — generateJUnitXml() produces standard JUnit XML for GitHub Actions, Jenkins, GitLab CI. Full XML escaping in both attributes and body text. Tests grouped by testCase.category. Failures include verdict, criteria results, and last 5 actions. Wired into generateReport() via format: 'junit'.

• Test suite — 51 vitest unit tests across 6 files. No browser, no LLM, no network. Runs in ~35ms (133ms total with transform/import).

Metrics

Metric	Value
Tests	51
Test execution time	35ms
Total pnpm test time	~133ms
New source files	3 (config.ts, webhook-sink.ts, reporters/junit.ts)
New test files	6
Edited files	5 (index.ts, cli.ts, test-report.ts, package.json, README.md)
Package size (dist/)	664K
New code added	~24K across 3 source files
Version	0.4.0 → 0.5.0

Test plan

• pnpm build — zero TypeScript errors
• pnpm test — 51/51 pass
• JUnit XML validated: no unescaped special chars in attributes or body text
• Config loading validated end-to-end: file → merge defaults → CLI override
• All exports verified: 10 new exports (defineConfig, defineTests, loadConfig, mergeConfig, toAgentConfig, generateJUnitXml, generateReport, WebhookSink, FilesystemSink, CompositeSink)
• Boolean CLI flags don't clobber config file (headless, vision, goalVerification)
• Reporters array replaces (not concats) on merge — ['junit'] replaces default ['json']