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/build.yaml

@@ -0,0 +1,17 @@
+when:
+  - event: pull_request
+
+steps:
+  - name: docker-build-api
+    image: woodpeckerci/plugin-docker-buildx
+    settings:
+      repo: git.unkin.net/unkin/forgebot-api
+      dockerfile: Dockerfile.api
+      dry_run: true
+
+  - name: docker-build-operator
+    image: woodpeckerci/plugin-docker-buildx
+    settings:
+      repo: git.unkin.net/unkin/forgebot-operator
+      dockerfile: Dockerfile.operator
+      dry_run: true