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

.woodpecker/test.yaml

@@ -0,0 +1,8 @@
+when:
+  - event: pull_request
+
+steps:
+  - name: test
+    image: golang:1.25
+    commands:
+      - go test -race -count=1 ./pkg/... ./internal/... ./api/...