chat-EOS fix: eos_token -> <turn|> (clean stop in generic apps)

gpu-pipelined/gemma4_12b_qat_decode_int4linsym_msdpa_g8/tokenizer/tokenizer_config.json

@@ -7,7 +7,7 @@
   "eoa_token": "<audio|>",
   "eoc_token": "<channel|>",
   "eoi_token": "<image|>",
-  "eos_token": "<eos>",
+  "eos_token": "<turn|>",
   "eot_token": "<turn|>",
   "escape_token": "<|\"|>",
   "etc_token": "<tool_call|>",
@@ -71,4 +71,4 @@
   "think_token": "<|think|>",
   "tokenizer_class": "GemmaTokenizer",
   "unk_token": "<unk>"
-}
+}