initial agent-mgr: app builder platform MVP

Go API server + Preact UI + Claude Code adapter.
- App-centric model (ideas, not repos)
- AgentProvider interface for multi-agent support
- K8s pod lifecycle for sandboxed agent sessions
- Gitea integration (create repos, push branches)
- WebSocket streaming for live session output
- Woodpecker CI/CD pipelines (kaniko build + kubectl deploy)

ui/embed.go

@@ -0,0 +1,17 @@
+package ui
+
+import (
+	"embed"
+	"io/fs"
+)
+
+//go:embed dist/*
+var distFS embed.FS
+
+func StaticFS() fs.FS {
+	sub, err := fs.Sub(distFS, "dist")
+	if err != nil {
+		return nil
+	}
+	return sub
+}