Fail the weekly run when the light client checkpoint is stale (#79)

The wallet now refreshes its light client specifications from this repository through the signed
config, so a wallet that never fell back no longer starts from the checkpoint its APK was built with.
That only helps if the checkpoint here is kept fresh.

light_client_specs.py --check-age DAYS reads the relay checkpoint's block number from light-client/,
compares it with the live head, and fails past DAYS. Code Quality runs it weekly with 60 days. The
README asks for the specifications to be regenerated before signing.

.github/workflows/code-quality.yml

@@ -88,6 +88,11 @@ jobs:
       - name: Targets signed and matching every served file
         run: python3 scripts/signed_config.py check
 
+      # A wallet that never fell back to its light client has no saved state, so its first fallback
+      # starts from this checkpoint; refreshed specifications reach wallets through the signed config.
+      - name: Light client checkpoint not stale
+        run: python3 scripts/light_client_specs.py --relay-rpc https://zagros-rpc.pezkuwichain.io --check-age 60
+
   chain-integrity:
     name: Chain Config Integrity
     runs-on: ubuntu-latest