## Why

The current tool system is too rigid. Tool types are hardcoded with compose templates, configs are simple key-value pairs, and the UI is a basic flat list. Users need a true "tool workshop" where they can:

1. **Define new tools** with either Docker Compose or Dockerfile
2. **Configure rich tool settings** including ports, commands, working directories, and volume mounts
3. **Create reusable config file collections** (e.g., dotfiles, IDE settings) that mount into containers
4. **Wait for tools to be ready** with configurable health/readiness probes before considering the build complete

This unlocks the platform from built-in tools to a true marketplace of user-defined and user-configured tools.

## What Changes

- **Enhance ToolType model**: Add `dockerfile_template`, `readiness_probe` (command + timeout), `build_context` field
- **Enhance ToolConfig model**: Add `port_override`, `start_command`, `working_directory`, `environment_variables`, `volumes`
- **Create ConfigFolder model**: Named collections of files mountable as volumes, with per-project overrides
- **Add readiness probe system**: Instance creation waits for probe command with configurable timeout
- **Unified Tool Workshop UI**: Single page replacing `/tool-configs` and `/tool-types` with:
  - Tool Type builder (compose or dockerfile)
  - Tool Config editor (split-pane with all new fields)
  - Config Folder manager (file collections with mount paths)
  - Live validation and preview
- **Update instance creation flow**: Support dockerfile builds, mount config folders, apply readiness probes
- **Database migrations**: New columns on `tool_types`, `tool_configs`; new `config_folders` table

## Capabilities

### New Capabilities
- `tool-workshop`: Unified tool definition, configuration, and deployment interface
- `config-folders`: Reusable per-user file collections mountable into containers with per-project overrides
- `readiness-probes`: Build-time health checks that wait for tools to be ready before marking instances as running

### Modified Capabilities
- `tool-types`: Enhanced with dockerfile support, readiness probes, build context
- `tool-config-management`: Extended with port overrides, volumes, environment variables, working directory
- `tool-instances`: Instance creation supports dockerfile builds, config folder mounts, probe waiting

## Impact

- **Backend**: 
  - Models: `ToolType`, `ToolConfig`, new `ConfigFolder`
  - API: New endpoints for config folders, updated tool type/config endpoints
  - Services: Docker build service (for dockerfiles), readiness probe service
  - Instance creation: Dockerfile build path, volume mounting, probe execution
- **Frontend**:
  - New `ToolWorkshopPage` component (replaces `/tool-configs` and `/tool-types`)
  - New components: Dockerfile editor, readiness probe config, config folder manager, volume mount editor
  - Updated routing and navigation
- **Database**: 
  - `tool_types`: Add `dockerfile_template`, `readiness_probe`, `build_context`
  - `tool_configs`: Add `port_override`, `start_command`, `working_directory`, `environment_variables`, `volumes`
  - New `config_folders` table
- **User Experience**: Users can now define entirely new tools, configure them richly, and reuse config collections across projects

## Supersedes

This change supersedes `tool-config-ui-rework` which scoped only to the UI rework and basic new fields. This is a comprehensive expansion of the tool system.