feat(catalog): class template editing

Templates were delete-and-recreate only. Adds PUT
/v1/catalog/class-templates/{id} across repository, service (sharing
the create-time validation), route, spec, and client; the classes tab
gets a pencil action that loads the row into the form with a
save/cancel affordance.

Generated with [Devin](https://devin.ai)

Co-Authored-By: Devin <158243242+devin-ai-integration[bot]@users.noreply.github.com>

apps/backend/openapi/bookra.openapi.yaml

@@ -1099,6 +1099,31 @@ paths:
         "400":
           description: Invalid request
   /v1/catalog/class-templates/{templateID}:
+    put:
+      tags: [Catalog]
+      operationId: updateClassTemplate
+      security:
+        - bearerAuth: []
+      parameters:
+        - in: path
+          name: templateID
+          required: true
+          schema:
+            type: string
+            format: uuid
+      requestBody:
+        required: true
+        content:
+          application/json:
+            schema:
+              $ref: "#/components/schemas/UpsertClassTemplateRequest"
+      responses:
+        "200":
+          description: Updated class template
+        "400":
+          description: Invalid input
+        "404":
+          description: Template not found
     delete:
       tags: [Catalog]
       operationId: deleteClassTemplate