This manual JSON parsing implementation has several issues:

1. It reinvents JSON parsing instead of using Go's standard encoding/json package
2. The comment "avoiding import cycle with encoding/json" is misleading - there's no import cycle with the standard library
3. The implementation is fragile and error-prone compared to json.Unmarshal

Replace this with:

func parseJSON(jsonStr string, target interface{}) error {
    return json.Unmarshal([]byte(jsonStr), target)
}

And remove the decodeJSON and readAll helper functions (lines 294-324).

Potential race condition: The map linterRules is accessed concurrently without synchronization. Multiple goroutines may append to the same slice simultaneously when different rules map to the same linter, causing data races.

Fix by using a mutex:

linterRules := make(map[string][]schema.UserRule)
var mu sync.Mutex

for result := range results {
    for _, linter := range result.linters {
        mu.Lock()
        linterRules[linter] = append(linterRules[linter], result.rule)
        mu.Unlock()
    }
}

Alternatively, collect all results first, then aggregate them in a single-threaded manner.

The help text still references a removed flag --openai-model gpt-5-mini. This flag was removed (as seen in the diff at line 58), but the example at line 44 still mentions it. Update the example to remove this reference.