feat(tui): standardize picker navigation keys (#22347)

## Why

Picker-style UI in the TUI has accumulated a mix of hardcoded navigation
keys. Some lists supported page movement, some did not; some accepted
Vim-like keys, while others only accepted arrows; and tabbed or
horizontally adjustable pickers had no shared keymap action for
left/right movement.

This PR makes picker/list navigation consistent and configurable so
users can rely on the same defaults across the TUI.

## What Changed

- Adds shared list keymap actions for:
  - vertical movement: `move_up`, `move_down`
  - horizontal movement: `move_left`, `move_right`
  - paging and jumps: `page_up`, `page_down`, `jump_top`, `jump_bottom`
- Adds defaults:
- Up/down: arrows, `Ctrl+P/N`, `Ctrl+K/J`, and plain `k/j` where text
input is not active
  - Page up/down: `PageUp/PageDown` and `Ctrl+B/F`
  - First/last: `Home/End`
  - Left/right: `Left/Right` and `Ctrl+H/L`
- Wires the shared list keymap through picker and list surfaces
including session resume, multi-select, tabbed selection lists,
settings-style lists, app-link selection, MCP elicitation,
request-user-input, and the OSS selection wizard.
- Keeps search behavior intact by reserving printable characters for
query text in searchable pickers.
- Updates keymap setup actions, config schema, snapshots, and focused
coverage for the new list actions.

## How to Test

1. Start Codex from this branch and open the session picker, for example
with an existing session history.
2. In the session list, verify that `Ctrl+J/K` moves the selection
down/up.
3. Verify that `Ctrl+F/B` pages down/up and `Home/End` jumps to the
first/last visible session.
4. Type printable search text such as `j` or `k` and confirm it updates
the query instead of navigating.
5. Focus a picker control that changes values horizontally, such as a
session picker toolbar control, and verify `Ctrl+H/L` changes the
focused value like left/right arrows.

Targeted tests run:

- `cargo test -p codex-tui keymap::tests::`
- `cargo test -p codex-tui keymap_setup::tests::`
- `cargo test -p codex-tui horizontal_list_keys`
- `cargo test -p codex-tui page_and_jump_navigation_use_list_keymap`
- `cargo test -p codex-tui ctrl_h_l_move_provider_selection`
- `cargo test -p codex-tui scroll_state::tests`
- `cargo test -p codex-tui
switching_tabs_changes_visible_items_and_clears_search`
- `cargo test -p codex-tui toggle_sort_key_reloads_with_new_sort`

Also ran `just write-config-schema`, `just fmt`, `just fix -p
codex-tui`, `just argument-comment-lint`, and `git diff --check`.

Note: `cargo test -p codex-tui` was attempted and still aborts in the
pre-existing
`tests::fork_last_filters_latest_session_by_cwd_unless_show_all` stack
overflow, which is unrelated to this branch.

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

@@ -1082,6 +1082,10 @@ impl BottomPane {
         popup_consts::standard_popup_hint_line_for_keymap(&self.keymap.list)
     }
 
+    pub(crate) fn list_keymap(&self) -> crate::keymap::ListKeymap {
+        self.keymap.list.clone()
+    }
+
     /// Replace one or more active views whose IDs are in `view_ids` with a
     /// generic list selection view.
     pub(crate) fn replace_active_views_with_selection_view(
@@ -1298,12 +1302,13 @@ impl BottomPane {
             request
         };
 
-        let modal = RequestUserInputOverlay::new(
+        let modal = RequestUserInputOverlay::new_with_keymap(
             request,
             self.app_event_tx.clone(),
             self.has_input_focus,
             self.enhanced_keys_supported,
             self.disable_paste_burst,
+            self.keymap.list.clone(),
         );
         self.pause_status_timer_for_modal();
         self.set_composer_input_enabled(
@@ -1342,7 +1347,7 @@ impl BottomPane {
                 tool_suggestion.suggest_type,
                 mcp_server_elicitation::ToolSuggestionType::Enable
             );
-            let view = AppLinkView::new(
+            let view = AppLinkView::new_with_keymap(
                 AppLinkViewParams {
                     app_id: tool_suggestion.tool_id.clone(),
                     title: tool_suggestion.tool_name.clone(),
@@ -1373,6 +1378,7 @@ impl BottomPane {
                     }),
                 },
                 self.app_event_tx.clone(),
+                self.keymap.list.clone(),
             );
             self.pause_status_timer_for_modal();
             self.set_composer_input_enabled(
@@ -1383,12 +1389,13 @@ impl BottomPane {
             return;
         }
 
-        let modal = McpServerElicitationOverlay::new(
+        let modal = McpServerElicitationOverlay::new_with_keymap(
             request,
             self.app_event_tx.clone(),
             self.has_input_focus,
             self.enhanced_keys_supported,
             self.disable_paste_burst,
+            self.keymap.list.clone(),
         );
         self.pause_status_timer_for_modal();
         self.set_composer_input_enabled(