chore: Stop explicitly copying pubspec.lock as flutter pub get generates it.

Dockerfile

@@ -14,9 +14,10 @@ RUN git config --global --add safe.directory /app
 RUN flutter config --enable-web
 
 # Copy dependency files first for better caching
-COPY pubspec.yaml pubspec.lock ./
+# Note: pubspec.lock will be generated by flutter pub get if missing
+COPY pubspec.yaml ./
 
-# Get dependencies
+# Get dependencies (generates pubspec.lock automatically)
 RUN flutter pub get
 
 # Copy source code