feat(tui): render structured network approval prompts in approval overlay (#11674)

### Description
#### Summary
Adds the TUI UX layer for structured network approvals

#### What changed
- Updated approval overlay to display network-specific approval context
(host/protocol).
- Added/updated TUI wiring so approval prompts show correct network
messaging.
- Added tests covering the new approval overlay behavior.

#### Why
Core orchestration can now request structured network approvals; this
ensures users see clear, contextual prompts in the TUI.

#### Notes
- UX behavior activates only when network approval context is present.

---------

Co-authored-by: Codex <199175422+chatgpt-codex-connector[bot]@users.noreply.github.com>

codex-rs/tui/src/chatwidget.rs

@@ -2394,6 +2394,7 @@ impl ChatWidget {
             id: ev.call_id,
             command: ev.command,
             reason: ev.reason,
+            network_approval_context: ev.network_approval_context,
             proposed_execpolicy_amendment: ev.proposed_execpolicy_amendment,
         };
         self.bottom_pane