feat(agent):Supports custom agent and chat experience with refactoring (#957)

* feat: add agent management functionality with creation, editing, and deletion

* feat: enhance agent creation and chat experience

- Added AgentWelcome component to display agent description on new thread creation.
- Improved agent name validation with availability check during agent creation.
- Updated NewAgentPage to handle agent creation flow more effectively, including enhanced error handling and user feedback.
- Refactored chat components to streamline message handling and improve user experience.
- Introduced new bootstrap skill for personalized onboarding conversations, including detailed conversation phases and a structured SOUL.md template.
- Updated localization files to reflect new features and error messages.
- General code cleanup and optimizations across various components and hooks.

* Refactor workspace layout and agent management components

- Updated WorkspaceLayout to use useLayoutEffect for sidebar state initialization.
- Removed unused AgentFormDialog and related edit functionality from AgentCard.
- Introduced ArtifactTrigger component to manage artifact visibility.
- Enhanced ChatBox to handle artifact selection and display.
- Improved message list rendering logic to avoid loading states.
- Updated localization files to remove deprecated keys and add new translations.
- Refined hooks for local settings and thread management to improve performance and clarity.
- Added temporal awareness guidelines to deep research skill documentation.

* feat: refactor chat components and introduce thread management hooks

* feat: improve artifact file detail preview logic and clean up console logs

* feat: refactor lead agent creation logic and improve logging details

* feat: validate agent name format and enhance error handling in agent setup

* feat: simplify thread search query by removing unnecessary metadata

* feat: update query key in useDeleteThread and useRenameThread for consistency

* feat: add isMock parameter to thread and artifact handling for improved testing

* fix: reorder import of setup_agent for consistency in builtins module

* feat: append mock parameter to thread links in CaseStudySection for testing purposes

* fix: update load_agent_soul calls to use cfg.name for improved clarity

* fix: update date format in apply_prompt_template for consistency

* feat: integrate isMock parameter into artifact content loading for enhanced testing

* docs: add license section to SKILL.md for clarity and attribution

* feat(agent): enhance model resolution and agent configuration handling

* chore: remove unused import of _resolve_model_name from agents

* feat(agent): remove unused field

* fix(agent): set default value for requested_model_name in _resolve_model_name function

* feat(agent): update get_available_tools call to handle optional agent_config and improve middleware function signature

---------

Co-authored-by: Willem Jiang <willem.jiang@gmail.com>

frontend/src/core/i18n/locales/en-US.ts

@@ -151,6 +151,41 @@ export const enUS: Translations = {
     chats: "Chats",
     recentChats: "Recent chats",
     demoChats: "Demo chats",
+    agents: "Agents",
+  },
+
+  // Agents
+  agents: {
+    title: "Agents",
+    description:
+      "Create and manage custom agents with specialized prompts and capabilities.",
+    newAgent: "New Agent",
+    emptyTitle: "No custom agents yet",
+    emptyDescription:
+      "Create your first custom agent with a specialized system prompt.",
+    chat: "Chat",
+    delete: "Delete",
+    deleteConfirm:
+      "Are you sure you want to delete this agent? This action cannot be undone.",
+    deleteSuccess: "Agent deleted",
+    newChat: "New chat",
+    createPageTitle: "Design your Agent",
+    createPageSubtitle:
+      "Describe the agent you want — I'll help you create it through conversation.",
+    nameStepTitle: "Name your new Agent",
+    nameStepHint:
+      "Letters, digits, and hyphens only — stored lowercase (e.g. code-reviewer)",
+    nameStepPlaceholder: "e.g. code-reviewer",
+    nameStepContinue: "Continue",
+    nameStepInvalidError:
+      "Invalid name — use only letters, digits, and hyphens",
+    nameStepAlreadyExistsError: "An agent with this name already exists",
+    nameStepCheckError: "Could not verify name availability — please try again",
+    nameStepBootstrapMessage:
+      "The new custom agent name is {name}. Let's bootstrap it's **SOUL**.",
+    agentCreated: "Agent created!",
+    startChatting: "Start chatting",
+    backToGallery: "Back to Gallery",
   },
 
   // Breadcrumb