chore: Remove PUBLISHING.md and update documentation for cost tracking

- Deleted PUBLISHING.md as it is no longer needed.
- Updated README.md and other files to clarify that usage and cost tracking is always on and cannot be disabled.
- Bumped version to 2.2.6 in setup.py and __init__.py to reflect these changes.

Author: abdulgeek

PUBLISHING.md

@@ -26,7 +26,7 @@ print(response.cost)   # 0.0012
 print(response.tokens) # 47
 ```
 
-**That's it.** No configuration. No complexity. Just results.
+**That's it.** No configuration. No complexity. Just results. Usage and cost tracking is always on—there is no option to disable it (required for usage attribution and cost visibility).
 
 ---
 
@@ -148,7 +148,7 @@ gpt-3.5-turbo        $0.000080
 
 ### Cost Tracking
 
-Every response includes cost information:
+Usage and cost tracking is always on; no option to disable. Every response includes cost information:
 
 ```python
 response = ck.ai('gpt-4', 'Write a story')

README.md

@@ -1,6 +1,9 @@
 """
 Cost Katana - The Simplest AI SDK for Python
 
+Usage and cost tracking is always on; there is no option to disable it
+(required for usage attribution and cost visibility).
+
 Example:
     import cost_katana as ck
 
@@ -40,7 +43,7 @@
     get_provider_from_model,
 )
 
-__version__ = "2.2.5"
+__version__ = "2.2.6"
 
 # Import configure function from client
 from .client import configure
@@ -99,7 +102,7 @@ def __repr__(self):
 
 
 class SimpleChat:
-    """Simple chat session with automatic cost tracking."""
+    """Simple chat session with automatic cost tracking (always on; no option to disable)."""
 
     def __init__(
         self, model: str, system_message: Optional[str] = None, **options: Any
@@ -165,6 +168,8 @@ def ai(
     """
     The simplest way to use AI in Python.
 
+    Usage and cost tracking is always on; no configuration required.
+
     Args:
         model: AI model name or constant (e.g., openai.gpt_4, 'gpt-4')
         prompt: Your prompt text

cost_katana/__init__.py

@@ -30,6 +30,8 @@ def configure(
     """
     Configure Cost Katana client globally.
 
+    Usage and cost tracking is always on; no option to disable.
+
     Args:
         api_key: Your Cost Katana API key (starts with 'dak_')
         base_url: Base URL for Cost Katana API (optional)

cost_katana/client.py

@@ -11,7 +11,12 @@
 
 @dataclass
 class Config:
-    """Configuration class for Cost Katana client"""
+    """
+    Configuration class for Cost Katana client.
+
+    Usage and cost tracking is always on; there is no option to disable it
+    (required for usage attribution and cost visibility).
+    """
 
     api_key: Optional[str] = None
     base_url: str = "https://api.costkatana.com"

cost_katana/config.py

@@ -14,7 +14,7 @@
 
 setup(
     name="cost-katana",
-    version="2.2.5",
+    version="2.2.6",
     author="Cost Katana Team",
     author_email="support@costkatana.com",
     description="The simplest way to use AI in Python with automatic cost tracking and optimization",