feat(editor): Implement drawing tools and advanced undo/redo

This commit significantly enhances the web spectrogram editor by implementing core drawing tools (line, ellipse, noise) and a robust undo/redo system.

-  and : Added redo button and styling.

- : Implemented canvas event handling, dynamic shape previews, and the  logic for lines and noise rectangles.

- : Now reconstructs the spectrogram from a clean base, allowing proper undo/redo.

- : Uses an improved color gradient for better visualization.

- : Stores original spectrogram data for persistent state management.

1 files changed, 22 insertions, 0 deletions

diff --git a/tools/editor/style.css b/tools/editor/style.css
index f610969..c02eb4a 100644
--- a/tools/editor/style.css
+++ b/tools/editor/style.css
@@ -33,3 +33,25 @@ h1, h2 {
     padding: 10px;
     cursor: pointer;
 }
+
+#undoButton {
+    background-color: #d9534f;
+    color: white;
+    border: none;
+    border-radius: 4px;
+}
+
+#undoButton:hover {
+    background-color: #c9302c;
+}
+
+#redoButton {
+    background-color: #5cb85c;
+    color: white;
+    border: none;
+    border-radius: 4px;
+}
+
+#redoButton:hover {
+    background-color: #4cae4c;
+}