Fix:update agent variable name rule (#11124)

### What problem does this PR solve?

change:

1. update agent variable name rule.
2. reset() in Canvas doesn't reset the env var.
3. correct log input binding in message component
### Type of change

- [x] Bug Fix (non-breaking change which fixes an issue)

agent/component/base.py

@@ -393,7 +393,7 @@ class ComponentParamBase(ABC):
 class ComponentBase(ABC):
     component_name: str
     thread_limiter = trio.CapacityLimiter(int(os.environ.get('MAX_CONCURRENT_CHATS', 10)))
-    variable_ref_patt = r"\{* *\{([a-zA-Z:0-9]+@[A-Za-z:0-9_.-]+|sys\.[a-z_]+)\} *\}*"
+    variable_ref_patt = r"\{* *\{([a-zA-Z:0-9]+@[A-Za-z0-9_.]+|sys\.[A-Za-z0-9_.]+|env\.[A-Za-z0-9_.]+)\} *\}*"
 
     def __str__(self):
         """