[sisyphus-bot] 

## Confirmed Bug

We have identified the root cause of this issue. The bug is in the config writing logic during installation.

### Root Cause

**File:** `src/cli/config-manager/write-omo-config.ts` (line 46)

```typescript
const merged = deepMergeRecord(existing, newConfig)
```

When a user runs `oh-my-opencode install` (even just to update settings), the installer:
1. Reads the existing config (with user's custom model settings)
2. Generates a **new** config based on detected provider availability
3. Calls `deepMergeRecord(existing, newConfig)` 
4. Writes the result back

**The problem:** `deepMergeRecord` overwrites values in `existing` with values from `newConfig`. This means your custom `"model": "openai/gpt-5.2-codex"` gets overwritten by the generated default model (e.g., `anthropic/claude-opus-4-6` if Claude is available).

### Why This Happens

Looking at `deepMergeRecord` (line 24-25):
```typescript
} else if (sourceValue !== undefined) {
  result[key] = sourceValue as TTarget[keyof TTarget]
}
```

Any defined value in the source (generated config) overwrites the target (user's config).

### Fix Approach

The merge direction should be reversed to respect user overrides:
```typescript
const merged = deepMergeRecord(newConfig, existing)
```

This ensures:
- User's explicit settings take precedence
- Only new/undefined keys get populated from generated defaults
- Custom model choices are preserved

### SEVERITY: HIGH

- **Impact:** User configuration is overwritten without consent
- **Affected Files:** 
  - `src/cli/config-manager/write-omo-config.ts`
  - `src/cli/config-manager/deep-merge-record.ts`
- **Trigger:** Running `oh-my-opencode install` (even for unrelated updates)

### Workaround (Until Fix)

Backup your config before running install:
```bash
cp ~/.config/opencode/oh-my-opencode.jsonc ~/.config/opencode/oh-my-opencode.jsonc.backup
```

We're working on a fix that will preserve your explicit model configurations.