Match Qwen Unicode number token boundaries

docs/issue111-tokenizer/product.jsonl

@@ -0,0 +1,2 @@
+{"case":"token_cache","old_tokens":89,"new_tokens":93,"old_prefix_miss":true,"warm_cached":95,"disk_cached":95,"warm_disk_state_exact":true}
+{"event":"test_resource_summary","elapsed_ms":18595,"peak":{"cpu_time_ns":19116354416,"resident_bytes":25394003968,"physical_bytes":77175615456,"peak_physical_bytes":77175648272,"disk_read_bytes":73502404608,"disk_write_bytes":470114304},"error":null}