Feat: text selection using mouse

src/input/mouse.rs

@@ -26,6 +26,12 @@ pub fn handle_mouse(ctx: &mut InputContext, mouse: MouseEvent, term: Rect) {
 
     match kind {
         MouseEventKind::Down(MouseButton::Left) => handle_click(ctx, col, row, term),
+        MouseEventKind::Drag(MouseButton::Left) | MouseEventKind::Moved => {
+            handle_editor_drag(ctx, col, row, term);
+        }
+        MouseEventKind::Up(MouseButton::Left) => {
+            ctx.app.editor_ctx.mouse_selecting = false;
+        }
         MouseEventKind::ScrollUp => handle_scroll(ctx, col, row, term, true),
         MouseEventKind::ScrollDown => handle_scroll(ctx, col, row, term, false),
         _ => {}
@@ -59,6 +65,55 @@ fn contains(area: Rect, col: u16, row: u16) -> bool {
     col >= area.x && col < area.x + area.width && row >= area.y && row < area.y + area.height
 }
 
+fn handle_editor_drag(ctx: &mut InputContext, col: u16, row: u16, term: Rect) {
+    if ctx.app.editor_ctx.mouse_selecting {
+        handle_editor_mouse(ctx, col, row, term, true);
+    }
+}
+
+fn handle_editor_mouse(ctx: &mut InputContext, col: u16, row: u16, term: Rect, dragging: bool) {
+    // Reconstruct editor area (mirrors render_modal_editor / ModalFrame::render_centered)
+    let width = (term.width * 80 / 100).max(40);
+    let height = (term.height * 60 / 100).max(10);
+    let modal_w = width.min(term.width.saturating_sub(4));
+    let modal_h = height.min(term.height.saturating_sub(4));
+    let mx = term.x + (term.width.saturating_sub(modal_w)) / 2;
+    let my = term.y + (term.height.saturating_sub(modal_h)) / 2;
+    // inner = area inside 1-cell border
+    let inner_x = mx + 1;
+    let inner_y = my + 1;
+    let inner_w = modal_w.saturating_sub(2);
+    let inner_h = modal_h.saturating_sub(2);
+
+    let show_search = ctx.app.editor_ctx.editor.search_active()
+        || !ctx.app.editor_ctx.editor.search_query().is_empty();
+    let reserved = 1 + if show_search { 1 } else { 0 };
+    let editor_y = inner_y + if show_search { 1 } else { 0 };
+    let editor_h = inner_h.saturating_sub(reserved);
+
+    if col < inner_x || col >= inner_x + inner_w || row < editor_y || row >= editor_y + editor_h {
+        return;
+    }
+
+    let scroll = ctx.app.editor_ctx.editor.scroll_offset();
+    let text_row = (row - editor_y) + scroll;
+    let text_col = col - inner_x;
+
+    if dragging {
+        if !ctx.app.editor_ctx.editor.is_selecting() {
+            ctx.app.editor_ctx.editor.start_selection();
+        }
+    } else {
+        ctx.app.editor_ctx.mouse_selecting = true;
+        ctx.app.editor_ctx.editor.cancel_selection();
+    }
+
+    ctx.app
+        .editor_ctx
+        .editor
+        .move_cursor_to(text_row, text_col);
+}
+
 fn handle_click(ctx: &mut InputContext, col: u16, row: u16, term: Rect) {
     // Sticky minimap intercepts all clicks
     if matches!(ctx.app.ui.minimap, MinimapMode::Sticky) {
@@ -745,8 +800,11 @@ fn handle_engine_click(ctx: &mut InputContext, col: u16, row: u16, area: Rect) {
 
 fn handle_modal_click(ctx: &mut InputContext, col: u16, row: u16, term: Rect) {
     match &ctx.app.ui.modal {
-        Modal::Editor | Modal::Preview => {
-            // Don't dismiss editor/preview on click
+        Modal::Editor => {
+            handle_editor_mouse(ctx, col, row, term, false);
+        }
+        Modal::Preview => {
+            // Don't dismiss preview on click
         }
         Modal::Confirm { .. } => {
             handle_confirm_click(ctx, col, row, term);