fix: update placeholder text in chat components for clarity

- Changed placeholder text in ChatComposerCardView and subtitle in ChatCollectionBackgroundStatusView to be more concise and user-friendly.

Author: ratulsarna

iosApp/iosApp/ChatUIKit/ChatScreenChromeView.swift

@@ -214,7 +214,7 @@ struct ChatComposerCardView: View {
 
                 ZStack(alignment: .topLeading) {
                     if state.inputText.isEmpty {
-                        Text("Ask OpenCode anything, @ for files, / for commands")
+                        Text("Ask anything...")
                             .font(.body)
                             .foregroundStyle(Color(.placeholderText))
                             .allowsHitTesting(false)

iosApp/iosApp/ChatUIKit/ChatViewController.swift

@@ -1009,7 +1009,7 @@ private final class ChatCollectionBackgroundStatusView: UIView {
             spinner.stopAnimating()
             spinner.isHidden = true
             titleLabel.text = "Start a conversation"
-            subtitleLabel.text = "Ask OpenCode anything — or paste a link to discuss."
+            subtitleLabel.text = "Ask anything..."
             subtitleLabel.isHidden = false
 
         case .hidden: