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

backend/app/analytics/event_recorder.py

@@ -4,6 +4,8 @@ from __future__ import annotations
 
 from typing import TYPE_CHECKING, Any, Protocol, runtime_checkable
 
+from psycopg.types.json import Json
+
 if TYPE_CHECKING:
     from psycopg_pool import AsyncConnectionPool
 
@@ -89,7 +91,7 @@ class PostgresAnalyticsRecorder:
             "duration_ms": duration_ms,
             "success": success,
             "error_message": error_message,
-            "metadata": metadata or {},
+            "metadata": Json(metadata or {}),
         }
         async with self._pool.connection() as conn:
             await conn.execute(_INSERT_SQL, params)

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

backend/app/conversation_tracker.py

@@ -9,7 +9,7 @@ if TYPE_CHECKING:
 
 _ENSURE_SQL = """
 INSERT INTO conversations
-    (thread_id, started_at, last_activity)
+    (thread_id, created_at, last_activity)
 VALUES
     (%(thread_id)s, NOW(), NOW())
 ON CONFLICT (thread_id) DO NOTHING

backend/app/llm.py

@@ -31,6 +31,16 @@ def create_llm(settings: Settings) -> BaseChatModel:
             api_key=settings.openai_api_key,
         )
 
+    if provider == "azure_openai":
+        from langchain_openai import AzureChatOpenAI
+
+        return AzureChatOpenAI(
+            azure_deployment=settings.azure_openai_deployment,
+            azure_endpoint=settings.azure_openai_endpoint,
+            api_key=settings.azure_openai_api_key,
+            api_version=settings.azure_openai_api_version,
+        )
+
     if provider == "google":
         from langchain_google_genai import ChatGoogleGenerativeAI
 
@@ -39,4 +49,7 @@ def create_llm(settings: Settings) -> BaseChatModel:
             google_api_key=settings.google_api_key,
         )
 
-    raise ValueError(f"Unknown LLM provider: '{provider}'. Use 'anthropic', 'openai', or 'google'.")
+    raise ValueError(
+        f"Unknown LLM provider: '{provider}'. "
+        "Use 'anthropic', 'openai', 'azure_openai', or 'google'."
+    )

backend/app/ws_handler.py

@@ -54,7 +54,10 @@ async def handle_user_message(
     interrupt_manager: InterruptManager | None = None,
 ) -> None:
     """Process a user message through the graph and stream results back."""
-    if session_manager.is_expired(thread_id):
+    # Touch first so new sessions are created before expiry check.
+    # For existing sessions, touch resets the sliding window.
+    existing = session_manager.get_state(thread_id)
+    if existing is not None and session_manager.is_expired(thread_id):
         msg = "Session expired. Please start a new conversation."
         await _send_json(ws, {"type": "error", "message": msg})
         return