feat(records): implement records mode for data entry

Implement a new "Records" mode for data entry.
- Add `RecordsNormal` and `RecordsEditing` to `AppMode` and `ModeKey` .
- `DataStore` now uses `IndexMap` and supports `sort_by_key()` to ensure
  deterministic row order.
- `ToggleRecordsMode` command now sorts data and switches to
  `RecordsNormal` .
- `EnterEditMode` command now respects records editing variants.
- `RecordsNormal` mode includes a new `o` keybinding to add a record row.
- `RecordsEditing` mode inherits from `Editing` and adds an `Esc` binding
  to return to `RecordsNormal` .
- Added `SortData` effect to trigger data sorting.
- Updated UI to display "RECORDS" and "RECORDS INSERT" mode names and
  styles.
- Updated keymaps, command registry, and view navigation to support these
  new modes.
- Added comprehensive tests for records mode behavior, including sorting
  and boundary conditions for Tab/Enter.

Co-Authored-By: fiddlerwoaroof/git-smart-commit (gemma-4-26B-A4B-it-UD-Q5_K_XL.gguf)

src/command/cmd/grid.rs

@@ -1,4 +1,5 @@
 use crate::model::cell::CellValue;
+use crate::ui::app::AppMode;
 use crate::ui::effect::{self, Effect};
 use crate::view::AxisEntry;
 
@@ -414,6 +415,8 @@ impl Cmd for ToggleRecordsMode {
         let mut effects: Vec<Box<dyn Effect>> = Vec::new();
         let records_name = "_Records".to_string();
 
+        effects.push(Box::new(effect::SortData));
+
         // Create (or replace) a _Records view and switch to it
         effects.push(Box::new(effect::CreateView(records_name.clone())));
         effects.push(Box::new(effect::SwitchView(records_name)));
@@ -435,6 +438,7 @@ impl Cmd for ToggleRecordsMode {
                 }));
             }
         }
+        effects.push(effect::change_mode(AppMode::RecordsNormal));
         effects.push(effect::set_status("Records mode"));
         effects
     }