feat: Kubernetes-like orchestration for LLM pipelines

[tbraun96]

Summary

This PR transforms llmnet into a Kubernetes-like orchestration platform for LLM pipelines. It introduces:

• Pipeline resource - The deployable unit (like K8s Deployment) with replicas, health checks, and rollout strategies
• Node management - Cluster member tracking with capacity and heartbeats
• Control plane API - REST endpoints for managing pipelines, nodes, and namespaces
• kubectl-like CLI - Familiar subcommands: deploy, get, scale, delete, context
• Context management - Switch between local and remote clusters (like kubeconfig)

New CLI Commands

# Control Plane
llmnet serve --control-plane           # Start control plane on :8181

# Pipeline Management
llmnet deploy pipeline.yaml            # Deploy pipeline
llmnet get pipelines                   # List pipelines
llmnet scale my-pipeline --replicas 3  # Scale
llmnet delete pipeline my-pipeline     # Delete

# Node Management  
llmnet get nodes                       # List nodes

# Context Management
llmnet context list                    # List contexts
llmnet context add remote --url http://10.0.0.1:8181
llmnet context use remote              # Switch context

# Status & Validation
llmnet status                          # Cluster status
llmnet validate config.json            # Validate composition

# Legacy Mode
llmnet run config.json                 # Run local pipeline

Architecture

┌─────────────────────────────────────────────────────────────┐
│                    LLMNet Control Plane                      │
│                      (llmnet serve)                          │
│  ┌──────────────┐  ┌──────────────┐  ┌──────────────────┐  │
│  │ API Server   │  │ Pipeline     │  │ Node Registry    │  │
│  │ :8181        │  │ Controller   │  │                  │  │
│  └──────────────┘  └──────────────┘  └──────────────────┘  │
└─────────────────────────────────────────────────────────────┘
                              │
         ┌────────────────────┼────────────────────┐
         ▼                    ▼                    ▼
   ┌───────────┐        ┌───────────┐        ┌───────────┐
   │  Node 1   │        │  Node 2   │        │  Node 3   │
   │ (worker)  │        │ (worker)  │        │ (worker)  │
   │ :8080     │        │ :8080     │        │ :8080     │
   └───────────┘        └───────────┘        └───────────┘

Design Philosophy

Mirrored K8s Features:

• Declarative configuration (JSON/YAML manifests)
• Contexts (like kubeconfig)
• Health checks (liveness/readiness)
• Horizontal scaling
• Labels and selectors
• Rollout strategies
• Namespaces

Excluded K8s Features (too complex for LLM orchestration):

• Complex scheduler (simple round-robin instead)
• etcd/HA control plane
• CRDs
• Network policies
• RBAC (simple API key auth instead)
• StatefulSets/DaemonSets

Test plan

• All 163 existing tests pass
• New cluster controller tests
• Control plane API endpoint tests
• Context management tests
• CLI parsing tests
• Manual testing: deploy/scale/delete workflow
• Manual testing: multi-node cluster setup