feat(01-01): create HTTP routes and Main entry point

- HealthRoutes with GET /health returning 'ok'
- Routes composition point for all route modules
- Main extends ZIOAppDefault with HOCON config
- ASCII sun banner with SUMMERCMS branding
- Server reads port from application.conf

summercms/src/api/HealthRoutes.scala

@@ -0,0 +1,20 @@
+package api
+
+import zio.http.*
+
+/** 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.
+  *
+  * Future endpoints:
+  *   - /ready will verify database connectivity
+  */
+object HealthRoutes {
+
+  val routes: Routes[Any, Response] =
+    Routes(
+      Method.GET / "health" -> Handler.text("ok")
+    )
+
+}

summercms/src/api/Routes.scala

@@ -0,0 +1,14 @@
+package api
+
+import zio.http.*
+
+/** Route composition point
+  *
+  * Aggregates all route modules in the application. Add new route modules here as they're created.
+  */
+object Routes {
+
+  val routes: Routes[Any, Response] =
+    HealthRoutes.routes
+
+}