fix(agent): skip tools for models without tool-call capability and parse image output

- Add SupportsToolCall to RunConfig; only inject tools into SDK when set
- Update twilight-ai to 497ad09 which adds SSE scanner 10MB buffer
  (fixes token-too-long on large image payloads) and parses the images
  array from OpenAI-compatible chat completions into StreamFilePart

internal/agent/agent.go

@@ -366,7 +366,7 @@ func (*Agent) buildGenerateOptions(cfg RunConfig, tools []sdk.Tool, prepareStep
 		sdk.WithSystem(cfg.System),
 		sdk.WithMaxSteps(-1),
 	}
-	if len(tools) > 0 {
+	if len(tools) > 0 && cfg.SupportsToolCall {
 		opts = append(opts, sdk.WithTools(tools))
 	}
 	if prepareStep != nil {