Add quick-add mode for categories

N (from anywhere) or n (in Category panel) opens an inline prompt
to add categories one after another without typing :add-cat each time.

- Yellow border + prompt distinguishes it from item-add (green)
- Enter / Tab adds the category and clears the buffer, staying open
- Esc returns to the category list
- Cursor automatically moves to the newly added category

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

src/ui/app.rs

@@ -18,6 +18,8 @@ pub enum AppMode {
     FormulaEdit { buffer: String },
     FormulaPanel,
     CategoryPanel,
+    /// Quick-add a new category: Enter adds and stays open, Esc closes.
+    CategoryAdd { buffer: String },
     /// Quick-add items to `category`: Enter adds and stays open, Esc closes.
     ItemAdd { category: String, buffer: String },
     ViewPanel,
@@ -89,6 +91,7 @@ impl App {
             AppMode::FormulaEdit { .. } => { self.handle_formula_edit_key(key)?; }
             AppMode::FormulaPanel => { self.handle_formula_panel_key(key)?; }
             AppMode::CategoryPanel => { self.handle_category_panel_key(key)?; }
+            AppMode::CategoryAdd { .. } => { self.handle_category_add_key(key)?; }
             AppMode::ItemAdd { .. } => { self.handle_item_add_key(key)?; }
             AppMode::ViewPanel => { self.handle_view_panel_key(key)?; }
             AppMode::TileSelect { .. } => { self.handle_tile_select_key(key)?; }
@@ -266,6 +269,12 @@ impl App {
                 }
             }
 
+            // N = quick-add a new category (opens Category panel in add mode)
+            (KeyCode::Char('N'), _) => {
+                self.category_panel_open = true;
+                self.mode = AppMode::CategoryAdd { buffer: String::new() };
+            }
+
             // ── Tile movement ──────────────────────────────────────────────
             // T = enter tile select mode (single key, no Ctrl needed)
             (KeyCode::Char('T'), _) => {
@@ -617,7 +626,11 @@ impl App {
                     }
                 }
             }
-            // a / o — open quick-add mode for the selected category
+            // n — add a new category
+            KeyCode::Char('n') => {
+                self.mode = AppMode::CategoryAdd { buffer: String::new() };
+            }
+            // a / o — open quick-add items mode for the selected category
             KeyCode::Char('a') | KeyCode::Char('o') => {
                 if let Some(cat_name) = cat_names.get(self.cat_panel_cursor) {
                     self.mode = AppMode::ItemAdd {
@@ -625,7 +638,7 @@ impl App {
                         buffer: String::new(),
                     };
                 } else {
-                    self.status_msg = "No category selected. Add a category first with :add-cat <name>.".to_string();
+                    self.status_msg = "No category selected. Press n to add a category first.".to_string();
                 }
             }
             _ => {}
@@ -633,6 +646,45 @@ impl App {
         Ok(())
     }
 
+    fn handle_category_add_key(&mut self, key: KeyEvent) -> Result<()> {
+        match key.code {
+            KeyCode::Esc => {
+                self.mode = AppMode::CategoryPanel;
+                self.status_msg = String::new();
+            }
+            KeyCode::Enter | KeyCode::Tab => {
+                let buf = if let AppMode::CategoryAdd { buffer } = &self.mode {
+                    buffer.trim().to_string()
+                } else { return Ok(()); };
+
+                if !buf.is_empty() {
+                    let result = command::dispatch(&mut self.model, &Command::AddCategory { name: buf.clone() });
+                    if result.ok {
+                        // Move cursor to the new category
+                        self.cat_panel_cursor = self.model.categories.len().saturating_sub(1);
+                        let count = self.model.categories.len();
+                        self.status_msg = format!("Added category \"{buf}\" ({count} total). Enter to add more, Esc to finish.");
+                        self.dirty = true;
+                    } else {
+                        self.status_msg = result.message.unwrap_or_default();
+                    }
+                }
+                // Stay in CategoryAdd for the next entry
+                if let AppMode::CategoryAdd { ref mut buffer } = self.mode {
+                    buffer.clear();
+                }
+            }
+            KeyCode::Char(c) => {
+                if let AppMode::CategoryAdd { ref mut buffer } = self.mode { buffer.push(c); }
+            }
+            KeyCode::Backspace => {
+                if let AppMode::CategoryAdd { ref mut buffer } = self.mode { buffer.pop(); }
+            }
+            _ => {}
+        }
+        Ok(())
+    }
+
     fn handle_item_add_key(&mut self, key: KeyEvent) -> Result<()> {
         match key.code {
             KeyCode::Esc => {
@@ -1013,8 +1065,9 @@ impl App {
             AppMode::Editing { .. } => "Enter:commit  Esc:cancel",
             AppMode::FormulaPanel => "n:new  d:delete  jk:nav  Esc:back",
             AppMode::FormulaEdit { .. } => "Enter:save  Esc:cancel  — type: Name = expression",
-            AppMode::CategoryPanel => "jk:nav  Space:cycle-axis  a:add-items  Esc:back",
-            AppMode::ItemAdd { category, .. } => "Enter:add & continue  Tab:same  Esc:done",
+            AppMode::CategoryPanel => "jk:nav  Space:cycle-axis  n:new-cat  a:add-items  Esc:back",
+            AppMode::CategoryAdd { .. } => "Enter:add & continue  Tab:same  Esc:done — type a category name",
+            AppMode::ItemAdd { .. } => "Enter:add & continue  Tab:same  Esc:done — type an item name",
             AppMode::ViewPanel => "jk:nav  Enter:switch  n:new  d:delete  Esc:back",
             AppMode::TileSelect { .. } => "hl:select  Enter:cycle  r/c/p:set-axis  Esc:back",
             AppMode::CommandMode { .. } => ":q quit  :w save  :import  :add-cat  :formula  :help",