# Spec: Config Profile Multi-Repo Mounts

## Requirements

### Functional

1. **FR-1**: A `git_mount` entry MAY include a `mappings` array.
2. **FR-2**: Each item in `mappings` MUST have `source_path` and `target_path`.
3. **FR-3**: If `mappings` is absent, `source_path` and `target_path` at the entry level MUST be treated as a single mapping (backward compatibility).
4. **FR-4**: The repository MUST be cloned exactly once per `git_mount` entry.
5. **FR-5**: Each mapping MUST create a separate Docker bind mount.
6. **FR-6**: Glob patterns in `source_path` MUST be expanded per mapping.
7. **FR-7**: Relative `target_path` values MUST be resolved against `working_directory`.
8. **FR-8**: The merge logic for included profiles MUST deduplicate by `(remote_url, branch)` within a single resolved profile's `git_mounts` list.

### Non-Functional

1. **NFR-1**: No database schema migration required.
2. **NFR-2**: Existing API responses must remain backward-compatible.
3. **NFR-3**: Frontend type-check must pass without errors.

## API Contracts

### ConfigProfile model (git_mounts field)

```json
{
  "git_mounts": [
    {
      "remote_url": "https://github.com/user/monorepo.git",
      "branch": "main",
      "mappings": [
        {"source_path": "packages/api", "target_path": "/app/api"},
        {"source_path": "packages/web", "target_path": "/app/web"}
      ]
    },
    {
      "remote_url": "https://github.com/user/docs.git",
      "source_path": ".",
      "target_path": "/docs",
      "branch": "main"
    }
  ]
}
```

### Validation rules

1. `mappings` must be a non-empty array if present.
2. Each mapping must have `source_path` (string) and `target_path` (string).
3. Either `mappings` OR (`source_path` AND `target_path`) must be present.
4. `remote_url` must be a valid HTTPS or SSH Git URL.

## Database Schema

No changes. `git_mounts` is stored as JSONB in `config_profiles.git_mounts`.

## Scenarios

### Scenario 1: Monorepo with multiple packages

**Given** a Config Profile with:
```json
{"git_mounts": [{
  "remote_url": "https://github.com/corp/monorepo.git",
  "branch": "main",
  "mappings": [
    {"source_path": "packages/api", "target_path": "/app/api"},
    {"source_path": "packages/web", "target_path": "/app/web"},
    {"source_path": "packages/shared", "target_path": "/app/shared"}
  ]
}]}
```

**When** the profile is applied to an instance

**Then**:
1. `corp/monorepo` is cloned once to `git-mounts/monorepo-{hash}/repo-clone`
2. Three bind mounts are created:
   - `{clone}/packages/api` → `/app/api`
   - `{clone}/packages/web` → `/app/web`
   - `{clone}/packages/shared` → `/app/shared`

### Scenario 2: Legacy single mapping (backward compatibility)

**Given** a Config Profile with:
```json
{"git_mounts": [{
  "remote_url": "https://github.com/user/repo.git",
  "source_path": "src",
  "target_path": "/workspace/src",
  "branch": "main"
}]}
```

**When** the profile is applied

**Then** the behavior is identical to before (single clone, single mount).

### Scenario 3: Glob expansion within mapping

**Given** a mapping with:
```json
{"source_path": "packages/*", "target_path": "/app/packages"}
```

**When** the repo is cloned and the glob is expanded

**Then** each matched directory is mounted as a separate bind mount with the relative path appended to the target:
- `{clone}/packages/api` → `/app/packages/api`
- `{clone}/packages/web` → `/app/packages/web`

## Test Strategy

1. Unit test `_resolve_single_git_mount` with `mappings` array
2. Unit test `_merge_git_mounts` with mappings deduplication
3. Integration test: profile with 3 mappings from same repo → verify single clone
4. Integration test: legacy profile without `mappings` → verify backward compatibility
5. Frontend unit test: GitMountEditor renders mappings form correctly
