chore: enable clippy::redundant_clone (#3489)

Created this PR by:

- adding `redundant_clone` to `[workspace.lints.clippy]` in
`cargo-rs/Cargol.toml`
- running `cargo clippy --tests --fix`
- running `just fmt`

Though I had to clean up one instance of the following that resulted:

```rust
let codex = codex;
```

codex-rs/tui/src/bottom_pane/chat_composer.rs

@@ -487,7 +487,7 @@ impl ChatComposer {
             } => {
                 // Hide popup without modifying text, remember token to avoid immediate reopen.
                 if let Some(tok) = Self::current_at_token(&self.textarea) {
-                    self.dismissed_file_popup_token = Some(tok.to_string());
+                    self.dismissed_file_popup_token = Some(tok);
                 }
                 self.active_popup = ActivePopup::None;
                 (InputResult::None, true)
@@ -546,7 +546,7 @@ impl ChatComposer {
                             Some(ext) if ext == "jpg" || ext == "jpeg" => "JPEG",
                             _ => "IMG",
                         };
-                        self.attach_image(path_buf.clone(), w, h, format_label);
+                        self.attach_image(path_buf, w, h, format_label);
                         // Add a trailing space to keep typing fluid.
                         self.textarea.insert_str(" ");
                     } else {
@@ -2123,7 +2123,7 @@ mod tests {
 
         // Re-add and test backspace in middle: should break the placeholder string
         // and drop the image mapping (same as text placeholder behavior).
-        composer.attach_image(path.clone(), 20, 10, "PNG");
+        composer.attach_image(path, 20, 10, "PNG");
         let placeholder2 = composer.attached_images[0].placeholder.clone();
         // Move cursor to roughly middle of placeholder
         if let Some(start_pos) = composer.textarea.text().find(&placeholder2) {
@@ -2182,7 +2182,7 @@ mod tests {
         let path1 = PathBuf::from("/tmp/image_dup1.png");
         let path2 = PathBuf::from("/tmp/image_dup2.png");
 
-        composer.attach_image(path1.clone(), 10, 5, "PNG");
+        composer.attach_image(path1, 10, 5, "PNG");
         // separate placeholders with a space for clarity
         composer.handle_paste(" ".into());
         composer.attach_image(path2.clone(), 10, 5, "PNG");
@@ -2231,7 +2231,7 @@ mod tests {
         assert!(composer.textarea.text().starts_with("[image 3x2 PNG] "));
 
         let imgs = composer.take_recent_submission_images();
-        assert_eq!(imgs, vec![tmp_path.clone()]);
+        assert_eq!(imgs, vec![tmp_path]);
     }
 
     #[test]

codex-rs/tui/src/bottom_pane/mod.rs

@@ -564,7 +564,7 @@ mod tests {
         let (tx_raw, rx) = unbounded_channel::<AppEvent>();
         let tx = AppEventSender::new(tx_raw);
         let mut pane = BottomPane::new(BottomPaneParams {
-            app_event_tx: tx.clone(),
+            app_event_tx: tx,
             frame_requester: FrameRequester::test_dummy(),
             has_input_focus: true,
             enhanced_keys_supported: false,

codex-rs/tui/src/bottom_pane/textarea.rs

@@ -649,9 +649,7 @@ impl TextArea {
     }
 
     fn add_element(&mut self, range: Range<usize>) {
-        let elem = TextElement {
-            range: range.clone(),
-        };
+        let elem = TextElement { range };
         self.elements.push(elem);
         self.elements.sort_by_key(|e| e.range.start);
     }