feat(V2-1a): Monorepo 구조 전환 — apps/desktop으로 V1 이동

- npm workspaces 루트 (apps/*, packages/*) 세팅
- V1 전체를 apps/desktop/으로 git mv (src, resources, tests, sidecar,
  scripts, electron.vite.config.ts, electron-builder.yml, vitest.config.ts,
  tsconfig.node.json, tsconfig.web.json)
- apps/desktop/package.json 신규 (name=@d3ro/desktop)
- productName: 'd3ro-voice' 명시 — app.getName()을 고정하여 userData 경로
  %APPDATA%\d3ro-voice\ 그대로 유지 (기존 DB/설정 연속성 보장)
- 루트 package.json을 workspace 루트로 재구성, 공통 devDep만 유지
  (typescript, eslint, prettier)
- turbo.json, tsconfig.base.json 추가 (Turborepo 자체 설치는 별도 sub-phase)
- memory/project_status.md 생성 (규칙 13)

검증:
- npm run typecheck 통과
- npm run build 통과 (electron-vite main+preload+renderer)
- npm run dev 실제 실행 → DB/핫키/Ollama 자동 실행 모두 정상

apps/desktop/src/main/ipc/chain-handlers.ts

@@ -0,0 +1,88 @@
+// src/main/ipc/chain-handlers.ts
+// Phase 10.4: Multi-LLM Chain IPC 핸들러
+
+import { ipcMain } from 'electron'
+import { IPC_CHANNELS } from '@shared/ipc-channels'
+import { ipcSuccess, ipcError, ErrorCode, D3ROError } from '@shared/errors'
+import { getChainService } from '../services/ChainService'
+import type {
+  CreateChainParams,
+  UpdateChainParams,
+  DeleteChainParams,
+  ExecuteChainParams
+} from '@shared/types'
+
+export function registerChainHandlers(): void {
+  ipcMain.handle(IPC_CHANNELS.CHAIN.GET_ALL, async () => {
+    return ipcSuccess(getChainService().getAll())
+  })
+
+  ipcMain.handle(
+    IPC_CHANNELS.CHAIN.CREATE,
+    async (_event, params: CreateChainParams) => {
+      try {
+        const result = getChainService().create(params)
+        return ipcSuccess(result)
+      } catch (err) {
+        return ipcError(
+          ErrorCode.ConfigWriteFailed,
+          `Failed to create chain: ${err instanceof Error ? err.message : String(err)}`
+        )
+      }
+    }
+  )
+
+  ipcMain.handle(
+    IPC_CHANNELS.CHAIN.UPDATE,
+    async (_event, params: UpdateChainParams) => {
+      try {
+        const result = getChainService().update(params)
+        return ipcSuccess(result)
+      } catch (err) {
+        if (err instanceof D3ROError && err.code === ErrorCode.ChainNotFound) {
+          return ipcError(ErrorCode.ChainNotFound, err.message)
+        }
+        return ipcError(
+          ErrorCode.ConfigWriteFailed,
+          `Failed to update chain: ${err instanceof Error ? err.message : String(err)}`
+        )
+      }
+    }
+  )
+
+  ipcMain.handle(
+    IPC_CHANNELS.CHAIN.DELETE,
+    async (_event, params: DeleteChainParams) => {
+      try {
+        getChainService().delete(params.id)
+        return ipcSuccess(undefined)
+      } catch (err) {
+        if (err instanceof D3ROError && err.code === ErrorCode.ChainNotFound) {
+          return ipcError(ErrorCode.ChainNotFound, err.message)
+        }
+        return ipcError(
+          ErrorCode.ConfigWriteFailed,
+          `Failed to delete chain: ${err instanceof Error ? err.message : String(err)}`
+        )
+      }
+    }
+  )
+
+  ipcMain.handle(
+    IPC_CHANNELS.CHAIN.EXECUTE,
+    async (_event, params: ExecuteChainParams) => {
+      try {
+        const result = await getChainService().execute(params.chainId, params.text)
+        return ipcSuccess(result)
+      } catch (err) {
+        if (err instanceof D3ROError) {
+          return ipcError(err.code, err.message)
+        }
+        return ipcError(
+          ErrorCode.ChainExecutionFailed,
+          `Chain execution failed: ${err instanceof Error ? err.message : String(err)}`
+        )
+      }
+    }
+  )
+}