fix(migration): remove auto model-to-category conversion (#764)

* chore(deps): upgrade @opencode-ai/plugin and sdk to 1.1.19

* docs(prometheus): add Question tool usage reminder

* fix(migration): remove auto model-to-category conversion

- Remove migrateAgentConfigToCategory call from migrateConfigFile
- User's explicit model/category settings are now preserved as-is
- No more unwanted deletion of agent configs (e.g., multimodal-looker)
- Add BUILTIN_AGENT_NAMES constant for future reference
- Update tests to reflect new behavior

* ci(sisyphus): add mandatory 'new branch + PR' todos for implementation tasks

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Co-authored-by: justsisyphus <justsisyphus@users.noreply.github.com>

.github/workflows/sisyphus-agent.yml

@@ -430,6 +430,10 @@ jobs:
           2. **CREATE TODOS IMMEDIATELY**: Right after reading, create your todo list using todo tools.
              - First todo: "Summarize issue/PR context and requirements"
              - Break down ALL work into atomic, verifiable steps
+             - **GIT WORKFLOW (MANDATORY for implementation tasks)**: ALWAYS include these final todos:
+               - "Create new branch from origin/BRANCH_PLACEHOLDER (NEVER push directly to BRANCH_PLACEHOLDER)"
+               - "Commit changes"
+               - "Create PR to BRANCH_PLACEHOLDER branch"
              - Plan everything BEFORE starting any work
 
           ---