feat(api): Add server info, network health, and resource management

[nfebe]

Server info endpoint returns hostname, public IPs, and network interfaces. Network health checks DNS resolution against multiple resolvers (8.8.8.8, 1.1.1.1, 9.9.9.9) with latency and tests external connectivity. Resource endpoints allow reading and updating container memory/CPU limits via docker update.

Closes #77, closes #79

[sourceant]

Code Review Summary

This PR adds several useful endpoints for server information, network health, and container resource management. The implementation is generally solid and follows existing patterns in the codebase.

🚀 Key Improvements

• Added resource limit management for containers and deployments.
• Implemented network health checks including DNS resolution and external connectivity.
• Included comprehensive test coverage for the new API endpoints and internal logic.

💡 Minor Suggestions

• Improve error handling and context usage in network calls.
• Consider struct-based validation for resource updates.

[sourceant]

Review complete. See the overview comment for a summary.

[sourceant]

The error from GetContainerResources is ignored here. If the update succeeded but the subsequent fetch fails, the client receives a partial/successful response that might be misleading.

Suggested change

	resources, _ := docker.GetContainerResources(id)
	resources, err := docker.GetContainerResources(id)
	if err != nil {
	c.JSON(http.StatusOK, gin.H{
	"message": "Resources updated, but failed to fetch current limits",
	"error": err.Error(),
	})
	return
	}

[sourceant]

Review complete. See the overview comment for a summary.