Upgrade runtime to Go 1.25 and add container orchestration.

Add a cache-optimized multi-stage Dockerfile with non-root runtime, compose service definitions for local/dev execution, CI Go version alignment, and docs/path cleanup updates.

Made-with: Cursor

docker-compose.yml

@@ -0,0 +1,17 @@
+services:
+  api:
+    build:
+      context: .
+      dockerfile: Dockerfile
+    image: momswap-backend:latest
+    container_name: momswap-backend-api
+    environment:
+      ADDR: ":8080"
+      ADMIN_PUBLIC_KEY: "${ADMIN_PUBLIC_KEY:-}"
+    ports:
+      - "8080:8080"
+    restart: unless-stopped
+    develop:
+      watch:
+        - action: rebuild
+          path: .