fix(agents): resolve skill placeholders in Goose (yaml) command output (#3374)

* fix(agents): resolve skill placeholders in Goose (yaml) command output

CommandRegistrar.register_commands resolves {SCRIPT}/__AGENT__ and the
$ARGUMENTS placeholder in the markdown and toml branches, but the yaml
branch (Goose recipes) called render_yaml_command directly, skipping
both. So extension/preset command bodies installed for Goose kept literal
{SCRIPT}, __AGENT__, and repo-relative script paths in the generated
.goose/recipes/*.yaml prompt. Mirror the markdown/toml branches: run
resolve_skill_placeholders + _convert_argument_placeholder on the body
before render_yaml_command.

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

* test(goose): assert positive placeholder replacements in recipe prompt

Per review: parse the generated recipe with yaml.safe_load and assert the
prompt contains the resolved values (.specify/scripts/, 'agent goose',
{{args}}), not merely that the literal tokens are absent — a wrong output
that happens to omit the exact strings would otherwise pass.

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

---------

Co-authored-by: Claude Fable 5 <noreply@anthropic.com>

src/specify_cli/agents.py

@@ -701,6 +701,12 @@ class CommandRegistrar:
                 )
                 output = self.render_toml_command(frontmatter, body, source_id)
             elif agent_config["format"] == "yaml":
+                body = self.resolve_skill_placeholders(
+                    agent_name, frontmatter, body, project_root
+                )
+                body = self._convert_argument_placeholder(
+                    body, "$ARGUMENTS", agent_config["args"]
+                )
                 output = self.render_yaml_command(
                     frontmatter, body, source_id, cmd_name
                 )