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

internal/provider/provider.go

@@ -0,0 +1,19 @@
+package provider
+
+type WebhookEvent struct {
+	Type       string
+	Action     string
+	Repository string
+	Ref        string
+	IssueNum   int
+	PRNum      int
+	CommentID  int64
+	Body       string
+	Author     string
+}
+
+type Provider interface {
+	ParseWebhook(body []byte, secret string) (*WebhookEvent, error)
+	PostComment(owner, repo string, issueOrPR int, body string) error
+	AddReaction(owner, repo string, commentID int64, reaction string) error
+}