feat: @uncaged/workflow-role-llm — role factory + zod@4 schema

Migrated from nerve/workflow-utils:
- createRole with zod@4 schema → typed meta + JSON Schema
- createLlmAdapter — LLM provider abstraction
- llmExtract/llmExtractWithRetry — structured output extraction
- decorateRole/withDryRun/onFail — role decorators
- buildDescriptorFromRoles — auto-generate descriptor from zod schemas
- Zero nerve-core dependencies
- 83 tests pass, biome clean

Closes #9
小橘 <xiaoju@shazhou.work>

tsconfig.json

@@ -15,5 +15,9 @@
     "composite": true,
     "outDir": "dist"
   },
-  "references": [{ "path": "packages/workflow" }, { "path": "packages/cli-workflow" }]
+  "references": [
+    { "path": "packages/workflow" },
+    { "path": "packages/workflow-role-llm" },
+    { "path": "packages/cli-workflow" }
+  ]
 }