Add presets system and convert back to Flask

- Convert from Microdot back to Flask
- Add presets system with CRUD operations
- Store presets in presets.json file
- Replace patterns section with presets grid
- Add preset editor with full configuration
- Add collapse/expand functionality to left panel
- Always show on/off presets in presets list
- Highlight active preset matching current tab settings
- Add 'Create from Current' button in preset editor

presets.json

@@ -0,0 +1,41 @@
+{
+    "blinker": {
+        "pattern": "blink",
+        "colors": [
+            "#12b533"
+        ],
+        "brightness": 127,
+        "delay": 100,
+        "n1": 10,
+        "n2": 10,
+        "n3": 10,
+        "n4": 10
+    },
+    "circler": {
+        "pattern": "circle",
+        "colors": [
+            "#9d3434",
+            "#cb5d5d"
+        ],
+        "brightness": 127,
+        "delay": 100,
+        "n1": 10,
+        "n2": 10,
+        "n3": 10,
+        "n4": 10
+    },
+    "pulser": {
+        "pattern": "pulse",
+        "colors": [
+            "#9f1d1d",
+            "#176d2d",
+            "#50309c"
+        ],
+        "brightness": 127,
+        "delay": 300,
+        "n1": 10,
+        "n2": 10,
+        "n3": 10,
+        "n4": 10
+    }
+}