refactor(backend): update data schemas

- schemas/orchestrator.py: update orchestrator schemas
- schemas/settings.py: update settings schemas
- schemas/user_agent.py: update user agent schemas

server/src/app/schemas/settings.py

@@ -41,6 +41,10 @@ class SettingsAdminForm(BaseModel):
         return value.strip()
 
 
+class SettingsSessionForm(BaseModel):
+    conversationRetentionDays: int = Field(default=3, ge=1, le=10)
+
+
 class SettingsLlmForm(BaseModel):
     mainProvider: str = Field(min_length=1, max_length=64)
     mainModel: str = Field(min_length=1, max_length=255)
@@ -159,6 +163,7 @@ class SettingsMailForm(BaseModel):
 class SettingsRead(BaseModel):
     companyForm: SettingsCompanyForm
     adminForm: SettingsAdminForm
+    sessionForm: SettingsSessionForm
     llmForm: SettingsLlmForm
     renderForm: SettingsRenderForm
     logForm: SettingsLogForm
@@ -168,6 +173,7 @@ class SettingsRead(BaseModel):
 class SettingsWrite(BaseModel):
     companyForm: SettingsCompanyForm
     adminForm: SettingsAdminForm
+    sessionForm: SettingsSessionForm
     llmForm: SettingsLlmForm
     renderForm: SettingsRenderForm
     logForm: SettingsLogForm