Add Flip filter with bool option support and calibration UI polish

- New FlipFilter with horizontal/vertical bool options (np.fliplr/flipud)
- Add bool option type to filter system (base.py validate, app.js toggle UI)
- Rearrange calibration preview: direction toggle above LED count
- Normalize direction/offset control heights, brighten offset icon

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

server/src/wled_controller/static/index.html

@@ -82,16 +82,14 @@
                     <div class="calibration-preview">
                         <!-- Screen with direction toggle, total LEDs, and offset -->
                         <div class="preview-screen">
+                            <button type="button" class="direction-toggle" onclick="toggleDirection()" title="Toggle direction">
+                                <span id="direction-icon">↻</span> <span id="direction-label">CW</span>
+                            </button>
                             <div class="preview-screen-total" onclick="toggleEdgeInputs()" title="Toggle edge LED inputs"><span id="cal-total-leds-inline">0</span> / <span id="cal-device-led-count-inline">0</span></div>
-                            <div class="preview-screen-controls">
-                                <button type="button" class="direction-toggle" onclick="toggleDirection()" title="Toggle direction">
-                                    <span id="direction-icon">↻</span> <span id="direction-label">CW</span>
-                                </button>
-                                <label class="offset-control" title="LED offset from LED 0 to start corner">
-                                    <span>⊕</span>
-                                    <input type="number" id="cal-offset" min="0" value="0" oninput="updateCalibrationPreview()">
-                                </label>
-                            </div>
+                            <label class="offset-control" title="LED offset from LED 0 to start corner">
+                                <span>⊕</span>
+                                <input type="number" id="cal-offset" min="0" value="0" oninput="updateCalibrationPreview()">
+                            </label>
                         </div>
 
                         <!-- Edge bars with span controls and LED count inputs -->