fix: make git clone fallback explicitly use main branch

The releases API returns 404 when no releases exist, causing the installer
to fall back to 'main'. However, the fallback clone was not explicitly
specifying a branch, which could cause issues if the repository's default
branch configuration is in an inconsistent state. Now the fallback clone
also explicitly uses --branch main to ensure consistent behavior.

install.sh

@@ -182,9 +182,11 @@ if ! step_done "source"; then
     git -C "$SRC_DIR" fetch --tags --quiet
     git -C "$SRC_DIR" checkout "$LATEST_TAG" --quiet
   else
+    # Try with explicit branch first, then fallback to explicit 'main' branch
     git clone --depth 1 --branch "$LATEST_TAG" \
       "https://github.com/${GITHUB_REPO}.git" "$SRC_DIR" 2>/dev/null \
-    || git clone --depth 1 "https://github.com/${GITHUB_REPO}.git" "$SRC_DIR"
+    || git clone --depth 1 --branch main \
+      "https://github.com/${GITHUB_REPO}.git" "$SRC_DIR"
   fi
   mark_done "source"
 fi