feat: harden generic preset, add LLM retry, and finish tooling/docs

- PatternDef.validate + Luhn-gated credit-card detection; de-overlap the
  generic phone/date/IP patterns; presets.swiss unchanged (production behavior)
- strip g/y flags from nameHint so .test() is stateless (latent footgun)
- openAICompatibleProvider: bounded retry on transient failures (network /
  timeout / 429 / 5xx), configurable via retries + retryDelayMs
- eslint + prettier + vitest coverage (97%); CI runs lint/format/coverage
- docs: README badges + new-option docs, SECURITY.md, issue/PR templates

26 tests passing; build emits ESM+CJS+types.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

vitest.config.ts

@@ -0,0 +1,11 @@
+import { defineConfig } from 'vitest/config';
+
+export default defineConfig({
+  test: {
+    coverage: {
+      provider: 'v8',
+      include: ['src/**/*.ts'],
+      reporter: ['text', 'html', 'lcov'],
+    },
+  },
+});