feat(01-02): add /ready endpoint with database connectivity check

- Add GET /ready endpoint that checks database connection
- Returns 200 'ready' when connected, 503 when not
- Update Routes to require DataSource dependency
- Provide dataSourceLayer in Main.scala
- Use 'hikari' prefix for HikariCP config to avoid ZIO config conflict

summercms/src/api/HealthRoutes.scala

@@ -1,20 +1,33 @@
 package api
 
+import zio.*
 import zio.http.*
+import javax.sql.DataSource
 
 /** Health check endpoints
   *
-  * Provides basic health check endpoint for load balancers and monitoring systems. The /health
-  * endpoint returns 200 OK when the server is running.
+  * Provides health check endpoints for load balancers and monitoring systems.
   *
-  * Future endpoints:
-  *   - /ready will verify database connectivity
+  * Endpoints:
+  *   - GET /health - Returns 200 OK when server is running (liveness probe)
+  *   - GET /ready - Returns 200 when database is connected, 503 when not (readiness probe)
   */
 object HealthRoutes {
 
-  val routes: Routes[Any, Response] =
+  val routes: Routes[DataSource, Response] =
     Routes(
-      Method.GET / "health" -> Handler.text("ok")
+      // Liveness probe - always 200 if server is running
+      Method.GET / "health" -> Handler.text("ok"),
+      // Readiness probe - checks database connectivity
+      Method.GET / "ready" -> handler {
+        ZIO.serviceWithZIO[DataSource] { ds =>
+          ZIO.attempt {
+            val conn = ds.getConnection
+            conn.close()
+          }.as(Response.text("ready"))
+            .catchAll(_ => ZIO.succeed(Response.status(Status.ServiceUnavailable)))
+        }
+      }
     )
 
 }

summercms/src/api/Routes.scala

@@ -1,6 +1,7 @@
 package api
 
 import zio.http.*
+import javax.sql.DataSource
 
 /** Route composition point
   *
@@ -8,7 +9,7 @@ import zio.http.*
   */
 object Routes {
 
-  val routes: Routes[Any, Response] =
+  val routes: Routes[DataSource, Response] =
     HealthRoutes.routes
 
 }