ci: add predict-student.c to the fuzz-smoke source list

The fuzz job compiles a hardcoded source list (not $(OBJS)), so the
train/serve file split broke its link. Add the new serving/format TU.

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>
Signed-off-by: mstrathman <matthew.strathman@gmail.com>

Author: mstrathman

.github/workflows/ci.yml

@@ -64,6 +64,7 @@ jobs:
             -Ivendor/ -I./ \
             fuzz/fuzz_predict.c sqlite-predict.c predict-forecast.c \
             predict-tabular.c predict-receipts.c predict-distill.c \
+            predict-student.c \
             vendor/sha256.c vendor/sqlite3.c -o fuzz_predict -lm -lpthread -ldl
           ./fuzz_predict -max_total_time=60 -max_len=512 fuzz/seeds