chore: define view model (#12949)

<!-- This is an auto-generated comment: release notes by coderabbit.ai
-->

## Summary by CodeRabbit

* **New Features**
* Introduced a chat interface with message list, empty state view, and
support for user, assistant, and system messages.
* Added a chat manager for session and message handling, including
session creation, message sending, and error management.
* Implemented various chat cell types (attachments, context references,
workflow status, loading, and error cells) with corresponding data
models and view models.
* Enabled asynchronous message sending from the input box with error
alerts and automatic session creation.
* Added workflow and context-related models for advanced chat features.

* **Enhancements**
* Improved UI responsiveness with table view updates and dynamic empty
state handling.
  * Provided a method to clear all attachments in the input box.

* **Bug Fixes / Style**
* Refined code formatting, access control, and minor stylistic
improvements across multiple files for consistency.

<!-- end of auto-generated comment: release notes by coderabbit.ai -->

packages/frontend/apps/ios/App/App.xcodeproj/project.pbxproj

@@ -3,7 +3,7 @@
 	archiveVersion = 1;
 	classes = {
 	};
-	objectVersion = 77;
+	objectVersion = 56;
 	objects = {
 
 /* Begin PBXBuildFile section */
@@ -92,6 +92,8 @@
 /* Begin PBXFileSystemSynchronizedRootGroup section */
 		C45499AB2D140B5000E21978 /* NBStore */ = {
 			isa = PBXFileSystemSynchronizedRootGroup;
+			exceptions = (
+			);
 			path = NBStore;
 			sourceTree = "<group>";
 		};
@@ -340,13 +342,9 @@
 			);
 			inputFileListPaths = (
 			);
-			inputPaths = (
-			);
 			name = "[CP] Embed Pods Frameworks";
 			outputFileListPaths = (
 			);
-			outputPaths = (
-			);
 			runOnlyForDeploymentPostprocessing = 0;
 			shellPath = /bin/sh;
 			shellScript = "\"${PODS_ROOT}/Target Support Files/Pods-AFFiNE/Pods-AFFiNE-frameworks.sh\"\n";