feat: publish Dever core with project scaffolding and versioned AI skills

.trellis/tasks/09-29-external-lib-ecosystems/check.jsonl

@@ -0,0 +1,3 @@
+{"file":".trellis/spec/backend/quality-guidelines.md","reason":"CLI、filesystem、offline fixture 和确定性测试"}
+{"file":".trellis/spec/backend/error-handling.md","reason":"resolver/cache/protocol failure 分类"}
+{"file":".trellis/tasks/09-29-external-lib-ecosystems/prd.md","reason":"生态子任务验收标准"}