chore: 升级 Trellis 并精简规则（09-05-trellis-upgrade-rule-cleanup）

.agents/skills/trellis-meta/references/local-architecture/context-injection.md

@@ -47,7 +47,7 @@ In both modes, JSONL files in the task directory are the manifest for spec/resea
 {"file": ".trellis/spec/backend/index.md", "reason": "Backend rules"}
 ```
 
-Readers should skip seed rows without a `file` field. When configuring JSONL, the AI should include only spec/research files, not pre-register code files that will be modified.
+Readers should skip rows without a `file` field (e.g. legacy `_example` placeholders). When configuring JSONL, the AI should include only spec/research files, not pre-register code files that will be modified.
 
 ## Active Task And Context Key