refactor(codebase): resolve all 134 flake8 violations and reduce cyclomatic complexity

Eliminated all flake8 linting violations across the codebase:

* W293 (87 violations): Removed trailing whitespace from blank lines in registry_loader.py, provider_manager.py, explanations.py, and utils.py
* W391 (13 violations): Removed trailing blank lines at end of file in provider implementations and strategy files
* F401 (4 violations): Removed unused datetime imports from registry_loader.py and builtins imports from utils.py and suggestions.py
* E302 (4 violations): Added missing blank lines before top-level class definitions in strategy.py, enums, base.py, and utils.py
* E261 (6 violations): Fixed inline comment spacing (single→double space before #) in ollama_openai.py and explanations.py
* E305 (1 violation): Added blank line between _query_model method and module-level comment in explanations.py
* E303 (1 violation): Removed extra blank line between methods in provider_manager.py
* E501 (1 violation): Broke long function signature in ai_interface.py._query_parallel() across multiple lines
* E251 (1 violation): Removed spaces around keyword parameter equals in explanations.py
* F841 (1 violation): Removed unused 'link' variable in provider_manager.py._init_providers()

Refactored 8 high-complexity functions to reduce cyclomatic complexity:

* AIModelInterface.query_model (12→6): Extracted _route_vendor_query() for vendor routing logic
* AIModelInterface.get_model_weights (12→4): Extracted _calculate_base_weight() helper
* AIModelInterface._build_messages (11→4): Extracted 5 vendor-specific message builders
* ProviderManager._init_providers (11→7): Extracted _init_provider_variants() for variant loop
* RegistryLoader._validate_registry (12→5): Extracted validation helper methods
* SmartPlotGenerator._create_scatter (14→8): Extracted dimension and title helpers
* plotgen (12→6): Extracted _extract_and_override_variables() to eliminate duplication
* VisualizationRecommender._apply_ensemble_scoring (13→4): Extracted recommendation collection helpers

Author: DYung26

.coverage

@@ -1,8 +1,8 @@
 from enum import Enum
 
+
 class StrategyName(str, Enum):
     ROUND_ROBIN = "round_robin"
     COST_OPTIMIZED = "cost_optimized"
     PERFORMANCE = "performance"
     FALLBACK_CHAIN = "fallback"
-

plotsense/core/ai_interface.py

@@ -6,7 +6,7 @@
 
 class AnthropicProvider(LLMProvider):
     """Provider integration for Anthropic's Claude models."""
-    
+
     LINK = "👉 https://console.anthropic.com/account/keys 👈"
 
     def __init__(self, api_key: str):
@@ -67,4 +67,3 @@ def validate_key(self) -> bool:
             return True
         except Exception:
             return False
-

plotsense/core/enums/strategy.py

@@ -88,4 +88,3 @@ def validate_key(self) -> bool:
         except Exception as e:
             print(f"⚠️ Azure OpenAI API key validation failed: {e}")
             return False
-

plotsense/core/providers/anthropic.py

@@ -1,6 +1,7 @@
 from abc import ABC, abstractmethod
 from typing import List
 
+
 class LLMProvider(ABC):
     """Abstract base class for LLM providers."""
 
@@ -22,4 +23,3 @@ def list_models(self) -> List[str]:
     @abstractmethod
     def validate_key(self) -> bool:
         pass
-

plotsense/core/providers/azure_openai.py

@@ -47,7 +47,7 @@ def query(
                 ]
             else:
                 # Text-only
-                contents = prompt 
+                contents = prompt
 
             self._init_client()
             if not self.client:

plotsense/core/providers/base.py

@@ -7,7 +7,7 @@
 
 class GroqProvider(LLMProvider):
     """Provider integration for Groq's fast inference API."""
-    
+
     LINK = "👉 https://console.groq.com/keys 👈"
 
     def __init__(self, api_key: str):

plotsense/core/providers/gemini.py

@@ -7,7 +7,7 @@
 
 class GroqOpenAIProvider(LLMProvider):
     """Provider for Groq models using the OpenAI-compatible SDK interface.
-    
+
     This variant uses Groq's OpenAI-compatible API endpoint, allowing use
     of the OpenAI SDK with Groq's infrastructure.
     """
@@ -74,4 +74,3 @@ def validate_key(self) -> bool:
             return bool(response)
         except Exception:
             return False
-

plotsense/core/providers/groq.py

@@ -23,8 +23,8 @@ def _init_client(self):
         if not self.client:
             # Default local Ollama endpoint
             self.client = OpenAI(
-                base_url="http://localhost:11434/v1", # Ollama’s OpenAI-compatible API
-                api_key=self.api_key or "ollama", # Dummy key for OpenAI client compatibility
+                base_url="http://localhost:11434/v1",  # Ollama’s OpenAI-compatible API
+                api_key=self.api_key or "ollama",  # Dummy key for OpenAI client compatibility
             )
 
     def query(self, prompt: str, model: str, **kwargs) -> str:
@@ -73,4 +73,3 @@ def validate_key(self) -> bool:
             return bool(response)
         except Exception:
             return False
-