test(geocoding): add unit tests + end-to-end smoke test script

**Unit tests (`bun test`, 42 checks, 0 deps)**

- `src/lib/__tests__/category-map.test.ts` locks in the Pelias→
  PlaceCategory priority resolution. Covers the ambiguous multi-category
  case (food beats retail for restaurants, transit beats professional
  for car rentals, transport:rail still maps to transit, …), the simple
  single-category paths, the layer-hint fallback, and regression cases
  from real Konstanz/Stuttgart/Köln venues observed during deploy
  verification.
- `src/lib/__tests__/cache.test.ts` covers LRU eviction order, TTL
  expiry, move-to-end on get (so frequently-read entries survive
  eviction), size tracking, and typed-value storage.

**Smoke test (`./scripts/smoke-test.sh` or `bun run test:smoke`)**

End-to-end curls against a running service, aimed at post-deploy
verification. Health endpoints, forward (venue + street fallback),
focus biasing, reverse geocoding, cache hit. 9 checks total.

Wired up as `test:smoke` in package.json so it runs alongside the
unit tests. Verified working: 42/42 unit tests green locally, 9/9
smoke checks green against the live Mac Mini deployment.

CLAUDE.md Testing section rewritten to reflect the new test layers.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

services/mana-geocoding/package.json

@@ -6,7 +6,8 @@
 	"scripts": {
 		"dev": "bun run --watch src/index.ts",
 		"start": "bun run src/index.ts",
-		"test": "bun test"
+		"test": "bun test",
+		"test:smoke": "./scripts/smoke-test.sh"
 	},
 	"dependencies": {
 		"hono": "^4.7.0"