Add Sort A-Z and Sort Z-A commands

Sorts all rows by the currently selected column using
locale-aware alphanumeric comparison (numeric: true).

Co-authored-by: Shelley <shelley@exe.dev>

app_test.go

@@ -98,7 +98,7 @@ func TestParseCSVString(t *testing.T) {
 func TestGetCommands(t *testing.T) {
 	reg := NewCommandRegistry()
 	cmds := reg.GetCommands()
-	if len(cmds) != 12 {
+	if len(cmds) != 14 {
 		t.Errorf("expected 12 commands, got %d", len(cmds))
 	}
 	// Check that all have IDs

commands.go

@@ -30,5 +30,7 @@ func (c *CommandRegistry) GetCommands() []Command {
 		{ID: "open-down", Name: "Insert Row Below", Shortcut: ""},
 		{ID: "open-left", Name: "Insert Column Left", Shortcut: ""},
 		{ID: "open-right", Name: "Insert Column Right", Shortcut: ""},
+		{ID: "sort-asc", Name: "Sort A-Z", Shortcut: ""},
+		{ID: "sort-desc", Name: "Sort Z-A", Shortcut: ""},
 	}
 }

frontend/src/main.js

@@ -607,6 +607,8 @@ async function loadCommands() {
             { ID: 'open-down', Name: 'Insert Row Below', Shortcut: '' },
             { ID: 'open-left', Name: 'Insert Column Left', Shortcut: '' },
             { ID: 'open-right', Name: 'Insert Column Right', Shortcut: '' },
+            { ID: 'sort-asc', Name: 'Sort A-Z', Shortcut: '' },
+            { ID: 'sort-desc', Name: 'Sort Z-A', Shortcut: '' },
         ];
     }
 }
@@ -706,6 +708,8 @@ async function executeCommand(id) {
         case 'open-down': doInsertRowBelow(); break;
         case 'open-left': doInsertColLeft(); break;
         case 'open-right': doInsertColRight(); break;
+        case 'sort-asc': doSort(true); break;
+        case 'sort-desc': doSort(false); break;
     }
 }
 
@@ -919,6 +923,19 @@ function doInsertColRight() {
     setStatus('Inserted column right');
 }
 
+// ===== Sorting =====
+function doSort(ascending) {
+    const col = state.cursor.col;
+    state.rows.sort((a, b) => {
+        const va = (a[col] || '').toLowerCase();
+        const vb = (b[col] || '').toLowerCase();
+        return ascending ? va.localeCompare(vb, undefined, { numeric: true })
+                         : vb.localeCompare(va, undefined, { numeric: true });
+    });
+    render();
+    setStatus(`Sorted by ${state.headers[col] || colLabel(col)} ${ascending ? 'A-Z' : 'Z-A'}`);
+}
+
 // ===== File loading =====
 async function loadFile(filePath) {
     try {