feat(05-02): wire template routes and budget generate endpoint in router

- Add /api/template route group: GET, PUT /, POST/PUT/DELETE items, PUT items/reorder
- Add POST /api/budgets/generate before /{id} routes to avoid chi treating 'generate' as an id param
- /items/reorder registered before /items/{itemId} for correct static-before-param routing

backend/internal/api/router.go

@@ -50,6 +50,7 @@ func NewRouter(queries *db.Queries, sessionSecret string, frontendFS fs.FS) http
 		r.Route("/api/budgets", func(r chi.Router) {
 			r.Get("/", h.ListBudgets)
 			r.Post("/", h.CreateBudget)
+			r.Post("/generate", h.GenerateBudget)
 			r.Get("/{id}", h.GetBudget)
 			r.Put("/{id}", h.UpdateBudget)
 			r.Delete("/{id}", h.DeleteBudget)
@@ -60,6 +61,15 @@ func NewRouter(queries *db.Queries, sessionSecret string, frontendFS fs.FS) http
 			r.Delete("/{id}/items/{itemId}", h.DeleteBudgetItem)
 		})
 
+		r.Route("/api/template", func(r chi.Router) {
+			r.Get("/", h.GetTemplate)
+			r.Put("/", h.UpdateTemplateName)
+			r.Post("/items", h.CreateTemplateItem)
+			r.Put("/items/reorder", h.ReorderTemplateItems)
+			r.Put("/items/{itemId}", h.UpdateTemplateItem)
+			r.Delete("/items/{itemId}", h.DeleteTemplateItem)
+		})
+
 		r.Get("/api/settings", h.GetSettings)
 		r.Put("/api/settings", h.UpdateSettings)
 	})