feat(ui): implement premium beige design system and ux refinements

backend/app/config.py

@@ -17,7 +17,7 @@ class Settings(BaseSettings):
 
     database_url: str
 
-    llm_provider: Literal["anthropic", "openai", "google"] = "anthropic"
+    llm_provider: Literal["anthropic", "openai", "azure_openai", "google"] = "anthropic"
     llm_model: str = "claude-sonnet-4-6"
 
     session_ttl_minutes: int = 30
@@ -34,6 +34,10 @@ class Settings(BaseSettings):
 
     anthropic_api_key: str = ""
     openai_api_key: str = ""
+    azure_openai_api_key: str = ""
+    azure_openai_endpoint: str = ""
+    azure_openai_api_version: str = "2024-12-01-preview"
+    azure_openai_deployment: str = ""
     google_api_key: str = ""
 
     @model_validator(mode="after")
@@ -41,6 +45,7 @@ class Settings(BaseSettings):
         key_map = {
             "anthropic": self.anthropic_api_key,
             "openai": self.openai_api_key,
+            "azure_openai": self.azure_openai_api_key,
             "google": self.google_api_key,
         }
         key = key_map.get(self.llm_provider, "")
@@ -49,4 +54,13 @@ class Settings(BaseSettings):
                 f"API key for provider '{self.llm_provider}' is required. "
                 f"Set the corresponding environment variable."
             )
+        if self.llm_provider == "azure_openai":
+            if not self.azure_openai_endpoint:
+                raise ValueError(
+                    "AZURE_OPENAI_ENDPOINT is required for azure_openai provider."
+                )
+            if not self.azure_openai_deployment:
+                raise ValueError(
+                    "AZURE_OPENAI_DEPLOYMENT is required for azure_openai provider."
+                )
         return self