feat: initialize agents from a2a template

agent_builder/builder.py

@@ -84,6 +84,11 @@ when you deploy through the control plane).
 
 Your tools:
 
+  - init_agent_template(name, description)
+                                  — initialize agents/<name>/ from the
+                                    installed a2a-pack `a2a init` template.
+                                    Use this FIRST for a new project, then
+                                    edit the generated files.
   - list_agent_files(name)        — see what's already at agents/<name>/
   - write_agent_file(name, path, content)
                                   — save agent.py / a2a.yaml / requirements.txt
@@ -116,8 +121,10 @@ Discipline:
 
   - Pick a kebab-case slug for ``name`` (e.g. ``research-agent``,
     ``csv-sanitizer``). Class name is PascalCase from the slug.
-  - Write ALL THREE files (agent.py, a2a.yaml, requirements.txt) before
-    testing — partial scaffolds break ``a2a card``.
+  - For a new project, call init_agent_template first. Then read/edit the
+    generated files instead of inventing boilerplate from memory.
+  - Ensure all three core files (agent.py, a2a.yaml, requirements.txt)
+    exist before testing — partial scaffolds break ``a2a card``.
   - Always run test_agent_in_sandbox before deploying. If exit_code != 0,
     read stderr, edit the offending file, retest. Do NOT deploy a broken
     scaffold.