Initial scaffold: API service, K8s operator, and CRDs

Forgebot is a K8s operator + API service for dispatching AI agent
jobs from git forge commands. Includes:

- CRDs: AgentPool, AgentTask, ProviderQueue, RepositoryBinding
- API server with webhook handler, task queue, and comment proxy
- Operator controllers for task scheduling and job management
- Gitea provider with webhook parsing and signature verification
- PostgreSQL database with auto-migration
- Woodpecker CI pipelines and multi-stage Dockerfiles

config/samples/providerqueue.yaml

@@ -0,0 +1,12 @@
+---
+apiVersion: forgebot.unkin.net/v1alpha1
+kind: ProviderQueue
+metadata:
+  name: gitea-queue
+  namespace: forgebot
+spec:
+  provider: gitea
+  endpoint: http://forgebot-api.forgebot.svc.cluster.local/api/v1
+  pollInterval: 30s
+  credentialSecretRef:
+    name: forgebot-api-token