feat: add OpenAPI spec (dev only) with typed frontend client

- Add springdoc-openapi 3.0.2 (supports Spring Boot 4) to backend
- Disable api-docs/swagger-ui in application.yaml (prod default)
- Enable both in application-dev.yaml; Swagger UI at /swagger-ui.html
- Add openapi-fetch (runtime) and openapi-typescript (dev) to frontend
- Add generate:api npm script — run with backend up to regenerate types
- Add src/lib/api.server.ts typed client factory (uses SvelteKit fetch)
- Gitignore src/lib/generated/api.ts (generated artifact)

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

frontend/package.json

@@ -13,9 +13,14 @@
 		"format": "prettier --write .",
 		"lint": "prettier --check . && eslint .",
 		"test:unit": "vitest",
-		"test": "npm run test:unit -- --run"
+		"test": "npm run test:unit -- --run",
+		"generate:api": "openapi-typescript http://localhost:8080/v3/api-docs -o ./src/lib/generated/api.ts"
+	},
+	"dependencies": {
+		"openapi-fetch": "^0.13.5"
 	},
 	"devDependencies": {
+		"openapi-typescript": "^7.8.0",
 		"@eslint/compat": "^1.4.0",
 		"@eslint/js": "^9.39.1",
 		"@inlang/paraglide-js": "^2.5.0",