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/database/postgres.go

@@ -0,0 +1,37 @@
+package database
+
+import (
+	"context"
+	"fmt"
+
+	"github.com/jackc/pgx/v5/pgxpool"
+)
+
+type DB struct {
+	Pool *pgxpool.Pool
+}
+
+func New(dsn string) (*DB, error) {
+	pool, err := pgxpool.New(context.Background(), dsn)
+	if err != nil {
+		return nil, fmt.Errorf("connect to postgres: %w", err)
+	}
+	if err := pool.Ping(context.Background()); err != nil {
+		pool.Close()
+		return nil, fmt.Errorf("ping postgres: %w", err)
+	}
+	db := &DB{Pool: pool}
+	if err := db.migrate(); err != nil {
+		pool.Close()
+		return nil, fmt.Errorf("run migrations: %w", err)
+	}
+	return db, nil
+}
+
+func (db *DB) Close() {
+	db.Pool.Close()
+}
+
+func (db *DB) Healthy(ctx context.Context) bool {
+	return db.Pool.Ping(ctx) == nil
+}