## Context

Currently, the system seeds built-in tool types (code-server, jupyter-notebook, opencode) on every startup via `seed_builtin_tool_types()` in `main.py`. These are marked with `is_builtin=True` in the database and have special protections preventing their deletion or modification. This creates a two-tier system.

## Goals / Non-Goals

**Goals:**
- Remove `is_builtin` field from ToolType model and API
- Remove startup seeding logic
- Make all tool types editable and deletable
- Preserve existing tool type data by converting built-ins to regular types

**Non-Goals:**
- Changing the actual tool type definitions (compose templates, ports, etc.)
- Adding new tool types
- Changing the tool type creation API schema

## Decisions

### 1. Data Migration Over Runtime Seeding

**Decision**: Move built-in tool definitions from Python code to a database migration.

**Rationale**:
- Makes built-ins regular database records
- Eliminates special-case code paths
- Allows users to modify or delete them freely
- Simplifies the codebase

### 2. Drop `is_builtin` Column

**Decision**: Remove the `is_builtin` column entirely rather than setting all to False.

**Rationale**:
- Clean schema with no dead columns
- No confusion about what the flag means
- Simpler model

## Risks / Trade-offs

**[Risk] Users accidentally delete preconfigured tools** → Mitigation: These are just regular tool types now; users can recreate them manually if needed. The system no longer auto-recreates them.

**[Risk] Existing code depends on `is_builtin` flag** → Mitigation: Comprehensive search and removal of all references.

## Migration Plan

1. Create Alembic migration to:
   - Add `definition_type` and `dockerfile_template` columns if not present (some built-ins use these)
   - Insert built-in tool types as regular records (if they don't exist)
   - Drop `is_builtin` column
2. Remove `seed_builtin_tool_types()` from `main.py`
3. Update `ToolType` model to remove `is_builtin`
4. Update API to remove built-in checks
5. Update frontend to remove built-in-specific UI

## Open Questions

- Should we keep a seed script for fresh installations? (Yes, as a one-time migration)