fix: detect already-current binary via SHA256 hash comparison

When the downloaded binary has the same SHA256 hash as the installed
binary, the upgrade already succeeded (or the binary was already at
the target release). Report this clearly instead of showing misleading
before/after versions when upstream has a stale version string.

Signed-off-by: Sebastian Mendel <info@sebastianmendel.de>

Author: CybotTM

scripts/installers/github_release_binary.sh

@@ -225,6 +225,17 @@ fi
 # - Clean fallback if ~/.local/bin version is removed
 # - System packages can still satisfy dependencies for other tools
 
+# Check if binary is already at target version by comparing SHA256 hashes
+# This catches cases where upstream version string is wrong (e.g., sd v1.1.0 reports 1.0.0)
+BINARY_ALREADY_CURRENT=""
+if [ -f "$BIN_DIR/$BINARY_NAME" ] && [ -f "$BINARY_PATH" ]; then
+  OLD_HASH="$(sha256sum "$BIN_DIR/$BINARY_NAME" 2>/dev/null | awk '{print $1}')"
+  NEW_HASH="$(sha256sum "$BINARY_PATH" 2>/dev/null | awk '{print $1}')"
+  if [ -n "$OLD_HASH" ] && [ -n "$NEW_HASH" ] && [ "$OLD_HASH" = "$NEW_HASH" ]; then
+    BINARY_ALREADY_CURRENT="true"
+  fi
+fi
+
 # Install
 if [ -n "$PRESERVE_DIR" ] && [ -n "$EXTRACT_DIR" ]; then
   # Tool requires full directory structure (e.g., GAM with bundled Python)
@@ -268,6 +279,9 @@ path="$(command -v "$BINARY_NAME" 2>/dev/null || true)"
 printf "[%s] before: %s\n" "$TOOL" "${before:-<none>}"
 printf "[%s] after:  %s\n" "$TOOL" "${after:-<none>}"
 if [ -n "$path" ]; then printf "[%s] path:   %s\n" "$TOOL" "$path"; fi
+if [ "$BINARY_ALREADY_CURRENT" = "true" ]; then
+  printf "[%s] note:   binary already matches target release %s (upstream version string may be stale)\n" "$TOOL" "$LATEST"
+fi
 
 # Refresh snapshot after successful installation
 refresh_snapshot "$TOOL"