feat: add CPU and memory resource limits per app

- Add cpu_limit (REAL) and memory_limit (INTEGER) columns to apps table
  via migration 007
- Add CPULimit and MemoryLimit fields to App model with full CRUD support
- Add resource limits fields to app edit form with human-friendly
  memory input (e.g. 256m, 1g, 512k)
- Pass CPU and memory limits to Docker container creation via
  NanoCPUs and Memory host config fields
- Extract Docker container creation helpers (buildEnvSlice, buildMounts,
  buildResources) for cleaner code
- Add formatMemoryBytes template function for display
- Add comprehensive tests for parsing, formatting, model persistence,
  and container options

internal/service/deploy/deploy.go

@@ -1094,14 +1094,28 @@ func (svc *Service) buildContainerOptions(
 		network = app.DockerNetwork.String
 	}
 
+	var cpuLimit float64
+
+	if app.CPULimit.Valid {
+		cpuLimit = app.CPULimit.Float64
+	}
+
+	var memoryLimit int64
+
+	if app.MemoryLimit.Valid {
+		memoryLimit = app.MemoryLimit.Int64
+	}
+
 	return docker.CreateContainerOptions{
-		Name:    "upaas-" + app.Name,
-		Image:   imageID.String(),
-		Env:     envMap,
-		Labels:  buildLabelMap(app, labels),
-		Volumes: buildVolumeMounts(volumes),
-		Ports:   buildPortMappings(ports),
-		Network: network,
+		Name:        "upaas-" + app.Name,
+		Image:       imageID.String(),
+		Env:         envMap,
+		Labels:      buildLabelMap(app, labels),
+		Volumes:     buildVolumeMounts(volumes),
+		Ports:       buildPortMappings(ports),
+		Network:     network,
+		CPULimit:    cpuLimit,
+		MemoryLimit: memoryLimit,
 	}, nil
 }