refactor: Go 二进制输出到 dist/ 目录，避免污染项目根目录

Taskfile.yml

@@ -12,7 +12,7 @@ tasks:
     desc: Build for current platform
     deps: [build:frontend]
     cmds:
-      - go build -ldflags "-s -w -X main.version={{.VERSION}}" -o {{.APP_NAME}}{{.EXE}} .
+      - go build -ldflags "-s -w -X main.version={{.VERSION}}" -o dist/{{.APP_NAME}}{{.EXE}} .
 
   build:frontend:
     desc: Build frontend with Vite
@@ -33,7 +33,7 @@ tasks:
     desc: Build and run
     deps: [default]
     cmds:
-      - ./{{.APP_NAME}}{{.EXE}}
+      - ./dist/{{.APP_NAME}}{{.EXE}}
 
   dev:
     desc: Run with go run (skip frontend build)
@@ -43,7 +43,7 @@ tasks:
   clean:
     desc: Clean build artifacts
     cmds:
-      - rm -rf dist/ {{.APP_NAME}}{{.EXE}} web/dist web/node_modules
+      - rm -rf dist/ web/dist web/node_modules
 
   tidy:
     desc: Tidy Go modules