Deduplicate CAS_GET_TOOL_DEFINITION, isRecord, toolHandler, and
structuredToolFromSchema between summarizer.ts and extract-fn.ts.
Both now use createCasReactor(provider, cas, opts) and only provide
their own systemPrompt.
小橘 <xiaoju@shazhou.work>
Instead of hardcoding 'completed: moderator returned END', the engine now
calls a summarizer (ReAct loop with cas_get tool) to produce a meaningful
summary of the workflow outcome before writing the __end__ node.
- New summarizer.ts following supervisor.ts pattern
- Uses extract scene LLM provider (falls back to raw completion.summary on failure)
- Tracks step contentHashes for summarizer context
- Schema: z.object({ summary: z.string() })
Refs #187, #188
小橘 <xiaoju@shazhou.work>
xiaoju