refactor: restructure project layout

- Move main process to electron/main/
- Move preload to electron/preload/
- Add shared types in electron/shared/
- Split redis-service into modular redis/ directory
- Flatten renderer to src/ (remove src/renderer/ nesting)
- Update electron.vite.config.ts paths
- Update tsconfig paths
- Output to electron-dist/

electron/main/redis/string.ts

@@ -0,0 +1,15 @@
+// src/main/redis/string.ts
+// String 操作
+import { getClient } from './connection'
+
+export async function getStringValue(id: string, key: string): Promise<string | null> {
+  const client = getClient(id)
+  if (!client) throw new Error(`Client ${id} not found`)
+  return client.get(key)
+}
+
+export async function setStringValue(id: string, key: string, value: string): Promise<void> {
+  const client = getClient(id)
+  if (!client) throw new Error(`Client ${id} not found`)
+  await client.set(key, value)
+}