feat(04-01): generate jobs and admin controllers, reject model imports

Scaffold pact.Job and pact.AdminController stubs with Winter YAML
assets, and fail summer build when models imports a sibling package.

Co-authored-by: Cursor <cursoragent@cursor.com>

internal/build/leaf.go

@@ -0,0 +1,81 @@
+package build
+
+import (
+	"fmt"
+	"go/parser"
+	"go/token"
+	"os"
+	"path/filepath"
+	"strconv"
+	"strings"
+)
+
+var modelsSiblingLeaves = []string{
+	"classes",
+	"controllers",
+	"console",
+	"jobs",
+	"middleware",
+	"updates",
+}
+
+func checkModelsLeaf(appDir string, m Manifest) error {
+	for _, p := range m.Plugins {
+		pluginDir := localModuleDir(appDir, p.Module)
+		if pluginDir == "" {
+			pluginDir = filepath.Join(appDir, "plugins", pluginName(p.ID))
+		}
+		if !underRoot(appDir, pluginDir) {
+			continue
+		}
+		modelsDir := filepath.Join(pluginDir, "models")
+		st, err := os.Stat(modelsDir)
+		if err != nil || !st.IsDir() {
+			continue
+		}
+		module, err := readModulePath(filepath.Join(pluginDir, "go.mod"))
+		if err != nil {
+			return err
+		}
+		if err := inspectModelsImports(p.ID, pluginDir, module, modelsDir); err != nil {
+			return err
+		}
+	}
+	return nil
+}
+
+func inspectModelsImports(pluginID, pluginDir, module, modelsDir string) error {
+	entries, err := os.ReadDir(modelsDir)
+	if err != nil {
+		return fmt.Errorf("build: read %s: %w", modelsDir, err)
+	}
+	fset := token.NewFileSet()
+	for _, entry := range entries {
+		name := entry.Name()
+		if entry.IsDir() || !strings.HasSuffix(name, ".go") {
+			continue
+		}
+		path := filepath.Join(modelsDir, name)
+		file, err := parser.ParseFile(fset, path, nil, parser.ImportsOnly)
+		if err != nil {
+			return fmt.Errorf("build: parse %s: %w", path, err)
+		}
+		rel, err := filepath.Rel(pluginDir, path)
+		if err != nil {
+			rel = filepath.Join("models", name)
+		}
+		for _, spec := range file.Imports {
+			imp, err := strconv.Unquote(spec.Path.Value)
+			if err != nil {
+				continue
+			}
+			for _, sib := range modelsSiblingLeaves {
+				prefix := module + "/" + sib
+				if imp == prefix || strings.HasPrefix(imp, prefix+"/") {
+					return fmt.Errorf("build: plugin %s: %s imports %s", pluginID, filepath.ToSlash(rel), imp)
+				}
+			}
+		}
+	}
+	return nil
+}