feat: initialize Nuanji (Warm Notes) project

- Base platform from base.git (ERP base: auth, core, config, message, workflow, plugin)
- Created erp-diary module skeleton (lib.rs, dto.rs, error.rs, event.rs, state.rs)
- Integrated erp-diary into workspace and erp-server
- Added DiaryModule registration in main.rs
- Added DiaryState FromRef in state.rs
- Diary routes mounted (empty routes, ready for implementation)
- Product design spec v1.2 preserved in docs/
- Implementation plan preserved in plans/

Cargo check: OK
Cargo test: OK (78+ base tests passing)

crates/erp-plugin/Cargo.toml

@@ -0,0 +1,30 @@
+[package]
+name = "erp-plugin"
+version = "0.1.0"
+edition = "2024"
+description = "ERP WASM 插件运行时 — 生产级 Host API"
+
+[dependencies]
+wasmtime = "43"
+wasmtime-wasi = "43"
+erp-core = { workspace = true }
+tokio = { workspace = true }
+serde = { workspace = true }
+serde_json = { workspace = true }
+sea-orm = { workspace = true }
+uuid = { workspace = true }
+chrono = { workspace = true }
+tracing = { workspace = true }
+thiserror = { workspace = true }
+dashmap = "6"
+toml = "0.8"
+axum = { workspace = true }
+utoipa = { workspace = true }
+async-trait = { workspace = true }
+sha2 = { workspace = true }
+base64 = "0.22"
+moka = { version = "0.12", features = ["sync"] }
+regex = "1"
+csv = { workspace = true }
+rust_xlsxwriter = { workspace = true }
+validator = { workspace = true }