Fix: bash brace-expansion corrupts JSON in update-convert-tool workflow

[Copilot]

Embedding a GitHub Actions expression as a bash default value — "${VAR:-${{ expr }}}" — causes bash to append a stray } when the expanded value is a JSON object, producing invalid JSON and failing the step with "Invalid JSON for features workflow input".

Root cause

When ${{ steps.metadata.outputs.features }} expands to e.g. {"minAPI":"1.2.2","multiConnection":"optional"}, the resulting bash line is:

FEATURES_SOURCE="${INPUT_FEATURES:-{"minAPI":"1.2.2","multiConnection":"optional"}}"

Bash counts the {…} inside the default as a balanced brace pair, so the } from the YAML literal that was intended to close ${…} instead becomes a trailing character appended to the value — giving …optional"}} (invalid JSON).

Fix

Pass the metadata outputs as env: variables (GitHub Actions handles assignment safely) and use an explicit conditional fallback instead of the literal-JSON-as-default pattern:

env:
    INPUT_FEATURES: ${{ inputs.features }}
    METADATA_FEATURES: ${{ steps.metadata.outputs.features }}

# Before — corrupts JSON value when INPUT_FEATURES is set
FEATURES_SOURCE="${INPUT_FEATURES:-${{ steps.metadata.outputs.features }}}"

# After — safe, no literal JSON in the script body
FEATURES_SOURCE="${INPUT_FEATURES:-}"
if [ -z "$FEATURES_SOURCE" ] || [ "$FEATURES_SOURCE" = "null" ]; then
  FEATURES_SOURCE="$METADATA_FEATURES"
fi

Applied to both the Build tool metadata JSON and Update Supabase database steps in update-convert-tool.yml.