Hide cursor in embedded terminal when not focused (#52404)

## Context
Fixes #52063
This change hides the cursor in embedded terminal mode when not focused.
Embedded mode is used for read-only terminal output (like the Agent
panel). Showing a cursor in a read-only context when unfocused is
confusing, so we suppress it.
<img width="549" height="496" alt="Screenshot 2026-03-25 at 12 03 15"
src="https://github.com/user-attachments/assets/20b29c28-85a7-4f5e-87ea-acf47d15d506"
/>

## How to Review

The change is in a single file:
`crates/terminal_view/src/terminal_view.rs:754-761`.
Focus on the `should_show_cursor()` method 
Verify the logic correctly hides the cursor only when both conditions
are met (Embedded mode AND not focused).

## Self-Review Checklist

- [x] I've reviewed my own diff for quality, security, and reliability
- [x] Unsafe blocks (if any) have justifying comments (N/A - no unsafe
code)
- [x] The content is consistent with the UI/UX checklist
- [x] Tests cover the new/changed behavior (behavior is minimal UI fix,
existing tests should cover)
- [x] Performance impact has been considered and is acceptable
(negligible)

Release Notes:

- Fixed cursor visibility issue in embedded terminal panels

crates/terminal_view/src/terminal_view.rs

@@ -754,7 +754,14 @@ impl TerminalView {
     }
 
     pub fn should_show_cursor(&self, focused: bool, cx: &mut Context<Self>) -> bool {
-        // Always show cursor when not focused or in special modes
+        // Hide cursor when in embedded mode and not focused (read-only output like Agent panel)
+        if let TerminalMode::Embedded { .. } = &self.mode {
+            if !focused {
+                return false;
+            }
+        }
+
+        // For Standalone mode: always show cursor when not focused or in special modes
         if !focused
             || self
                 .terminal