ci: update fuzz target list to the v2 names

The Fuzz workflow step was still iterating the old v0.1 target names (parse_radio_config, cobs_decoder_feed, cobs_roundtrip, command_roundtrip, cobs_decoder_multi_frame, cobs_chunk_invariant). After the Protocol v2 rewrite only five targets exist: decoder_feed, frame_roundtrip, lora_config_roundtrip, parse_command, parse_device_message. Update the workflow to match.

.github/workflows/ci.yml

@@ -127,7 +127,7 @@ jobs:
       - name: Smoke-run every target
         working-directory: fuzz
         run: |
-          for target in parse_command parse_radio_config cobs_decoder_feed cobs_roundtrip command_roundtrip cobs_decoder_multi_frame cobs_chunk_invariant; do
+          for target in decoder_feed frame_roundtrip lora_config_roundtrip parse_command parse_device_message; do
             echo "── $target ──"
             cargo +nightly fuzz run "$target" --target x86_64-unknown-linux-gnu -- -max_total_time=60
           done