fix: prevent air from deleting the whole tmp folder, used for visual diff task

.air.toml

@@ -1,11 +1,11 @@
 root = "."
-tmp_dir = "tmp"
+tmp_dir = "tmp/air"
 
 [build]
-  cmd = "go build -tags nofrontend -o ./tmp/renewcms ./cmd/server"
-  bin = "tmp/renewcms"
+  cmd = "go build -tags nofrontend -o ./tmp/air/renewcms ./cmd/server"
+  bin = "tmp/air/renewcms"
   delay = 500
-  exclude_dir = ["tmp", "bin", "data", "web", "features", "docs", "internal/infrastructure/assets/dist", ".claude"]
+  exclude_dir = ["tmp", "tmp/air", "bin", "data", "web", "features", "docs", "internal/infrastructure/assets/dist", ".claude"]
   exclude_regex = ["_test.go"]
   include_ext = ["go", "html"]
   log = "build-errors.log"