refactor(command): pre-resolve cell key and grid dimensions in CmdContext

Refactor command system to pre-resolve cell key and grid dimensions
in CmdContext, eliminating repeated GridLayout construction.

Key changes:
- Add cell_key, row_count, col_count to CmdContext
- Replace generic CmdRegistry::register with
  register/register_pure/register_nullary
- Cell commands (clear-cell, yank, paste) now take explicit CellKey
- Update keymap dispatch to use new interactive() method
- Special-case "search" buffer in SetBuffer effect
- Update tests to populate new context fields

This reduces code duplication and makes command execution more
efficient by computing layout once at context creation time.

Co-Authored-By: fiddlerwoaroof/git-smart-commit (unsloth/Qwen3.5-35B-A3B-GGUF:Q5_K_M)

src/command/keymap.rs

@@ -165,7 +165,7 @@ impl Keymap {
         let binding = self.lookup(key, mods)?;
         match binding {
             Binding::Cmd { name, args } => {
-                let cmd = registry.parse(name, args).ok()?;
+                let cmd = registry.interactive(name, args, ctx).ok()?;
                 Some(cmd.execute(ctx))
             }
             Binding::Prefix(sub) => Some(vec![Box::new(SetTransientKeymap(sub.clone()))]),
@@ -267,7 +267,7 @@ impl KeymapSet {
         normal.bind_args(KeyCode::Char('u'), ctrl, "scroll-rows", vec!["-5".into()]);
 
         // Cell operations
-        normal.bind(KeyCode::Char('x'), none, "clear-selected-cell");
+        normal.bind(KeyCode::Char('x'), none, "clear-cell");
         normal.bind(KeyCode::Char('p'), none, "paste");
 
         // View

src/ui/app.rs

@@ -11,6 +11,7 @@ use crate::import::wizard::ImportWizard;
 use crate::model::cell::CellValue;
 use crate::model::Model;
 use crate::persistence;
+use crate::view::GridLayout;
 
 #[derive(Debug, Clone, PartialEq)]
 pub enum AppMode {
@@ -101,6 +102,8 @@ impl App {
 
     pub fn cmd_context(&self, key: KeyCode, mods: KeyModifiers) -> CmdContext<'_> {
         let view = self.model.active_view();
+        let layout = GridLayout::new(&self.model, view);
+        let (sel_row, sel_col) = view.selected;
         CmdContext {
             model: &self.model,
             mode: &self.mode,
@@ -120,6 +123,9 @@ impl App {
             cat_panel_cursor: self.cat_panel_cursor,
             view_panel_cursor: self.view_panel_cursor,
             tile_cat_idx: self.tile_cat_idx,
+            cell_key: layout.cell_key(sel_row, sel_col),
+            row_count: layout.row_count(),
+            col_count: layout.col_count(),
             key_code: key,
             key_modifiers: mods,
         }
@@ -220,11 +226,26 @@ mod tests {
         app.apply_effects(effects);
     }
 
+    fn enter_advance_cmd(app: &App) -> crate::command::cmd::EnterAdvance {
+        use crate::command::cmd::CursorState;
+        let view = app.model.active_view();
+        let cursor = CursorState {
+            row: view.selected.0,
+            col: view.selected.1,
+            row_count: 3,
+            col_count: 2,
+            row_offset: 0,
+            col_offset: 0,
+        };
+        crate::command::cmd::EnterAdvance { cursor }
+    }
+
     #[test]
     fn enter_advance_moves_down_within_column() {
         let mut app = two_col_model();
         app.model.active_view_mut().selected = (0, 0);
-        run_cmd(&mut app, &crate::command::cmd::EnterAdvance);
+        let cmd = enter_advance_cmd(&app);
+        run_cmd(&mut app, &cmd);
         assert_eq!(app.model.active_view().selected, (1, 0));
     }
 
@@ -233,7 +254,8 @@ mod tests {
         let mut app = two_col_model();
         // row_max = 2 (A,B,C), col 0 → should wrap to (0, 1)
         app.model.active_view_mut().selected = (2, 0);
-        run_cmd(&mut app, &crate::command::cmd::EnterAdvance);
+        let cmd = enter_advance_cmd(&app);
+        run_cmd(&mut app, &cmd);
         assert_eq!(app.model.active_view().selected, (0, 1));
     }
 
@@ -241,7 +263,8 @@ mod tests {
     fn enter_advance_stays_at_bottom_right() {
         let mut app = two_col_model();
         app.model.active_view_mut().selected = (2, 1);
-        run_cmd(&mut app, &crate::command::cmd::EnterAdvance);
+        let cmd = enter_advance_cmd(&app);
+        run_cmd(&mut app, &cmd);
         assert_eq!(app.model.active_view().selected, (2, 1));
     }
 

src/ui/effect.rs

@@ -289,7 +289,12 @@ pub struct SetBuffer {
 }
 impl Effect for SetBuffer {
     fn apply(&self, app: &mut App) {
-        app.buffers.insert(self.name.clone(), self.value.clone());
+        // "search" is special — it writes to search_query for backward compat
+        if self.name == "search" {
+            app.search_query = self.value.clone();
+        } else {
+            app.buffers.insert(self.name.clone(), self.value.clone());
+        }
     }
 }