docs: split model source records and unify project instructions (#113)

* docs: split model sources and consolidate project instructions

* docs: normalize empty model navigation footer

docs/model-sources/providers/deepseek/README.md

@@ -0,0 +1,21 @@
+# DeepSeek：来源导航
+
+[总索引](../../README.md) · [官网证据与边界](SOURCES.md)
+
+本目录包含 8 个单模型文件、2 个单接入面文件。核验日期与状态来自迁移前记录。
+
+## 接入面
+
+- [compute/providers/deepseek.json](access/providers--deepseek.md)
+- [compute/model-specs/deepseek.json](access/model-specs--deepseek.md)
+
+## 模型
+
+- [`deepseek-chat`](models/deepseek-chat.md)
+- [`deepseek-flash`](models/deepseek-flash.md)
+- [`deepseek-reasoner`](models/deepseek-reasoner.md)
+- [`deepseek-v4-flash`](models/deepseek-v4-flash.md)
+- [`deepseek-v4-flash-0731`](models/deepseek-v4-flash-0731.md)
+- [`deepseek-v4-flash-vision-exp`](models/deepseek-v4-flash-vision-exp.md)
+- [`deepseek-v4-pro`](models/deepseek-v4-pro.md)
+- [`deepseek-v4-pro-0813`](models/deepseek-v4-pro-0813.md)