chore: use rich to format logs (#177)

Summary:

Test Plan:
Before
<img width="1189" alt="image"
src="https://github.com/user-attachments/assets/b92b321e-3b89-4b17-8459-1b449dc8c087"
/>
After
<img width="1279" alt="image"
src="https://github.com/user-attachments/assets/eaa0b09a-bf29-43e7-a8c0-abcd7f87e8df"
/>


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* #178
* __->__ #177

Author: ehhuang

src/llama_stack_client/_utils/_logs.py

@@ -1,5 +1,6 @@
 import os
 import logging
+from rich.logging import RichHandler
 
 logger: logging.Logger = logging.getLogger("llama_stack_client")
 httpx_logger: logging.Logger = logging.getLogger("httpx")
@@ -10,6 +11,7 @@ def _basic_config() -> None:
     logging.basicConfig(
         format="[%(asctime)s - %(name)s:%(lineno)d - %(levelname)s] %(message)s",
         datefmt="%Y-%m-%d %H:%M:%S",
+        handlers=[RichHandler(rich_tracebacks=True)],
     )