chore: apply cargo fmt across workspace and update docs

- Run cargo fmt on all Rust crates for consistent formatting
- Update CLAUDE.md with WASM plugin commands and dev.ps1 instructions
- Update wiki: add WASM plugin architecture, rewrite dev environment docs
- Minor frontend cleanup (unused imports)

crates/erp-plugin-test-sample/src/lib.rs

@@ -0,0 +1,68 @@
+//! WASM 测试插件 — 验证插件端 API
+
+use serde_json::json;
+
+wit_bindgen::generate!({
+    path: "../erp-plugin-prototype/wit/plugin.wit",
+    world: "plugin-world",
+});
+
+use crate::erp::plugin::host_api;
+use crate::exports::erp::plugin::plugin_api::Guest;
+
+struct TestPlugin;
+
+impl Guest for TestPlugin {
+    fn init() -> Result<(), String> {
+        host_api::log_write("info", "测试插件初始化成功");
+
+        let data = json!({"sku": "TEST-001", "name": "测试商品", "quantity": 100}).to_string();
+        let result = host_api::db_insert("inventory_item", data.as_bytes())
+            .map_err(|e| format!("db_insert 失败: {}", e))?;
+
+        let record: serde_json::Value =
+            serde_json::from_slice(&result).map_err(|e| format!("解析结果失败: {}", e))?;
+
+        host_api::log_write(
+            "info",
+            &format!(
+                "插入成功: id={}, tenant_id={}",
+                record["id"].as_str().unwrap_or("?"),
+                record["tenant_id"].as_str().unwrap_or("?")
+            ),
+        );
+
+        Ok(())
+    }
+
+    fn on_tenant_created(tenant_id: String) -> Result<(), String> {
+        host_api::log_write("info", &format!("租户创建: {}", tenant_id));
+        let data = json!({"name": "默认分类", "tenant_id": tenant_id}).to_string();
+        host_api::db_insert("inventory_category", data.as_bytes())
+            .map_err(|e| format!("创建默认分类失败: {}", e))?;
+        Ok(())
+    }
+
+    fn handle_event(event_type: String, payload: Vec<u8>) -> Result<(), String> {
+        host_api::log_write("info", &format!("处理事件: {}", event_type));
+        let data: serde_json::Value =
+            serde_json::from_slice(&payload).map_err(|e| format!("解析失败: {}", e))?;
+
+        if event_type == "workflow.task.completed" {
+            let order_id = data["order_id"].as_str().unwrap_or("unknown");
+            let update = json!({"status": "approved"}).to_string();
+            host_api::db_update("purchase_order", order_id, update.as_bytes(), 1)
+                .map_err(|e| format!("更新失败: {}", e))?;
+
+            let evt = json!({"order_id": order_id, "status": "approved"}).to_string();
+            host_api::event_publish("purchase_order.approved", evt.as_bytes())
+                .map_err(|e| format!("发布事件失败: {}", e))?;
+
+            host_api::log_write("info", &format!("采购单 {} 审批完成", order_id));
+        }
+
+        Ok(())
+    }
+}
+
+export!(TestPlugin);