TUI/Core: preserve duplicate skill/app mention selection across submit + resume (#10855)

## What changed

- In `codex-rs/core/src/skills/injection.rs`, we now honor explicit
`UserInput::Skill { name, path }` first, then fall back to text mentions
only when safe.
- In `codex-rs/tui/src/bottom_pane/chat_composer.rs`, mention selection
is now token-bound (selected mention is tied to the specific inserted
`$token`), and we snapshot bindings at submit time so selection is not
lost.
- In `codex-rs/tui/src/chatwidget.rs` and
`codex-rs/tui/src/bottom_pane/mod.rs`, submit/queue paths now consume
the submit-time mention snapshot (instead of rereading cleared composer
state).
- In `codex-rs/tui/src/mention_codec.rs` and
`codex-rs/tui/src/bottom_pane/chat_composer_history.rs`, history now
round-trips mention targets so resume restores the same selected
duplicate.
- In `codex-rs/tui/src/bottom_pane/skill_popup.rs` and
`codex-rs/tui/src/bottom_pane/chat_composer.rs`, duplicate labels are
normalized to `[Repo]` / `[App]`, app rows no longer show `Connected -`,
and description space is a bit wider.

<img width="550" height="163" alt="Screenshot 2026-02-05 at 9 56 56 PM"
src="https://github.com/user-attachments/assets/346a7eb2-a342-4a49-aec8-68dfec0c7d89"
/>
<img width="550" height="163" alt="Screenshot 2026-02-05 at 9 57 09 PM"
src="https://github.com/user-attachments/assets/5e04d9af-cccf-4932-98b3-c37183e445ed"
/>


## Before vs now

- Before: selecting a duplicate could still submit the default/repo
match, and resume could lose which duplicate was originally selected.
- Now: the exact selected target (skill path or app id) is preserved
through submit, queue/restore, and resume.

## Manual test

1. Build and run this branch locally:
   - `cd /Users/daniels/code/codex/codex-rs`
   - `cargo build -p codex-cli --bin codex`
   - `./target/debug/codex`
2. Open mention picker with `$` and pick a duplicate entry (not the
first one).
3. Confirm duplicate UI:
   - repo duplicate rows show `[Repo]`
   - app duplicate rows show `[App]`
   - app description does **not** start with `Connected -`
4. Submit the prompt, then press Up to restore draft and submit again.  
   Expected: it keeps the same selected duplicate target.
5. Use `/resume` to reopen the session and send again.  
Expected: restored mention still resolves to the same duplicate target.

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

@@ -30,6 +30,7 @@ pub(crate) struct GenericDisplayRow {
     pub display_shortcut: Option<KeyBinding>,
     pub match_indices: Option<Vec<usize>>, // indices to bold (char positions)
     pub description: Option<String>,       // optional grey text after the name
+    pub category_tag: Option<String>,      // optional right-side category label
     pub disabled_reason: Option<String>,   // optional disabled message
     pub is_disabled: bool,
     pub wrap_indent: Option<usize>, // optional indent for wrapped lines
@@ -337,6 +338,10 @@ fn build_full_line(row: &GenericDisplayRow, desc_col: usize) -> Line<'static> {
         }
         full_spans.push(desc.clone().dim());
     }
+    if let Some(tag) = row.category_tag.as_deref().filter(|tag| !tag.is_empty()) {
+        full_spans.push("  ".into());
+        full_spans.push(tag.to_string().dim());
+    }
     Line::from(full_spans)
 }