fix: include provider and model name in billing error message (#20510)

Merged via /review-pr -> /prepare-pr -> /merge-pr.

Prepared head SHA: 40dbdf62e8
Co-authored-by: echoVic <16428813+echoVic@users.noreply.github.com>
Co-authored-by: gumadeiras <5599352+gumadeiras@users.noreply.github.com>
Reviewed-by: @gumadeiras

src/agents/pi-embedded-runner/run/payloads.ts

@@ -72,6 +72,7 @@ export function buildEmbeddedRunPayloads(params: {
   config?: OpenClawConfig;
   sessionKey: string;
   provider?: string;
+  model?: string;
   verboseLevel?: VerboseLevel;
   reasoningLevel?: ReasoningLevel;
   toolResultFormat?: ToolResultFormat;
@@ -104,6 +105,7 @@ export function buildEmbeddedRunPayloads(params: {
         cfg: params.config,
         sessionKey: params.sessionKey,
         provider: params.provider,
+        model: params.model,
       })
     : undefined;
   const rawErrorMessage = lastAssistantErrored