Review

High

• [x] AUTO-FIX: Cobra parse errors return generic exit code 1 instead of usage exit code 2: Execute sends every cmd.ExecuteContext error through writeError, and writeError only maps custom/client errors, so unknown flags or bad flag values violate the required CLI error contract. <!-- triage: plan Unit 3 test scenario requires "Cobra usage errors exit with code 2"; map flag-parse errors to ExitUsage -->

Medium

• [x] AUTO-FIX: Invalid base URL configuration returns a generic error instead of a usage/config error: screenote.NewClient errors from internal/cli/root.go:84 fall through writeError as internal_error with exit 1, despite malformed --base-url/config being a usage-style failure. <!-- triage: wrap NewClient config error as usageError (exit 2), consistent with error contract -->
• [x] AUTO-FIX: Malformed pagination parameters can bypass stable JSON API errors: pagination_params calls to_i on raw params in app/controllers/api/base_controller.rb:50, so structured values such as limit[x]=1 raise instead of returning machine-readable validation JSON. <!-- triage: plan wants stable JSON errors; coerce/guard param types so malformed values return validation JSON not a 500 -->
• [x] AUTO-FIX: Malformed screenshot upload payloads can bypass stable JSON API errors: app/controllers/api/v1/screenshots_controller.rb:34 assumes any present image param has tempfile, original_filename, and content_type, so image=not-file raises instead of returning validation JSON. <!-- triage: guard that image param is an uploaded file, else return validation JSON — aligns with stable-error contract -->

Nit