Add drag-and-drop for presets and colors, max_colors validation, and 2D grid layout

- Add drag-and-drop to reorder presets in tabs (2D grid layout)
- Add drag-and-drop to reorder colors within presets
- Add max_colors field to pattern definitions
- Hide color section when max_colors is 0
- Validate color count against pattern max_colors limit
- Store presets in 2D grid format (3 columns)
- Remove left panel from tab content, show only presets
- Update color palette to show swatches instead of hex codes
- Improve preset editor UI with visual color swatches

db/pattern.json

@@ -1,46 +1,54 @@
 {
     "on": {
             "min_delay": 10,
-            "max_delay": 10000
+            "max_delay": 10000,
+            "max_colors": 1
         },
-        "off": {
-            "min_delay": 10,
-            "max_delay": 10000
-        },
-        "rainbow": {
-            "Step Rate": "n1",
-            "min_delay": 10,
-            "max_delay": 10000
-        },
-        "transition": {
-            "min_delay": 10,
-            "max_delay": 10000
-        },
-        "chase": {
-            "Colour 1 Length": "n1",
-            "Colour 2 Length": "n2",
-            "Step 1": "n3",
-            "Step 2": "n4",
-            "min_delay": 10,
-            "max_delay": 10000
-        },
-        "pulse": {
-            "Attack": "n1",
-            "Hold": "n2",
-            "Decay": "n3",
-            "min_delay": 10,
-            "max_delay": 10000
-        },
-        "circle": {
-            "Head Rate": "n1",
-            "Max Length": "n2",
-            "Tail Rate": "n3",
-            "Min Length": "n4",
-            "min_delay": 10,
-            "max_delay": 10000
-        },
-        "blink": {
-            "min_delay": 10,
-            "max_delay": 10000
-        }
-    }
+    "off": {
+        "min_delay": 10,
+        "max_delay": 10000,
+        "max_colors": 0
+    },
+    "rainbow": {
+        "n1": "Step Rate",
+        "min_delay": 10,
+        "max_delay": 10000,
+        "max_colors": 0
+    },
+    "transition": {
+        "min_delay": 10,
+        "max_delay": 10000,
+        "max_colors": 10
+    },
+    "chase": {
+        "n1": "Colour 1 Length",
+        "n2": "Colour 2 Length",
+        "n3": "Step 1",
+        "n4": "Step 2",
+        "min_delay": 10,
+        "max_delay": 10000,
+        "max_colors": 2
+    },
+    "pulse": {
+        "n1": "Attack",
+        "n2": "Hold",
+        "n3": "Decay",
+        "min_delay": 10,
+        "max_delay": 10000,
+        "max_colors": 10
+    },
+    "circle": {
+        "n1": "Head Rate",
+        "n2": "Max Length",
+        "n3": "Tail Rate",
+        "n4": "Min Length",
+        "min_delay": 10,
+        "max_delay": 10000,
+        "max_colors": 2
+    },
+    "blink": {
+        "min_delay": 10,
+        "max_delay": 10000,
+        "max_colors": 10
+    }
+}