Update: 将子项目从 submodule 转为完整内容

- 移除 GovAI, nomifun-tauri, 算力盒子 的 submodule 引用
- 添加所有子项目的完整源代码
- 保留原始 .git 为 .git.bak 备份

nomifun-tauri/crates/backend/nomifun-db/Cargo.toml

@@ -0,0 +1,18 @@
+[package]
+name = "nomifun-db"
+version.workspace = true
+edition.workspace = true
+
+[dependencies]
+nomifun-common.workspace = true
+sqlx = { workspace = true, features = ["migrate"] }
+async-trait.workspace = true
+fs2.workspace = true
+serde.workspace = true
+serde_json.workspace = true
+thiserror.workspace = true
+tracing.workspace = true
+
+[dev-dependencies]
+tokio.workspace = true
+tempfile = "3"