Add SayoDevice support, 15 key pads and theme styles

Second protocol family (8089:000b) behind a new backend seam, 15 key and 3 knob pads, Knobs North plus the style and colour grid, Windows import fix, window resize fix.

docs/adding-a-pad.md

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+# Adding a pad the app doesn't know yet
+
+If MacroPad finds your pad but says it isn't supported, this is the whole
+process. It takes one command and one issue.
+
+## Start here: ask the pad
+
+Install MacroPad, plug your pad in, and run:
+
+```
+macropad detect
+```
+
+On most pads in this family that's the whole job. It asks the pad how many keys and knobs it has, reads back what's currently bound, and prints a report. Paste that into [an issue](https://github.com/Probler-Yt/MacroPad/issues) and your pad gets added to the known list.
+
+The app offers the same thing: when it sees a pad it doesn't recognise, the panel has an **Ask the pad what it is** button.
+
+## How it decides
+
+Detection is read only, and the pad has to pass two tests before the app will write anything to it:
+
+1. It answers the `0xFB` query with a sensible key and knob count.
+2. It then reports a full layer, describing exactly the control slots that count implies.
+
+A pad from a different family fails one of those, and the app leaves it alone rather than guessing.
+
+The pad reports how many keys and knobs it has, but not how they're arranged, so the first guess at rows and columns may be wrong. Fix it with [Edit layout](#-if-the-drawing-doesnt-match-your-pad) and the drawing will match your hardware.
+
+## If it doesn't answer
+
+Some pads in this family speak an older protocol and won't answer. Working those out needs a capture of the vendor software, the same process used for this one. You'll need `MINI_KEYBOARD.exe` and Wine.
+
+#### Capture what the vendor software sends
+
+1. **See what your pad is:**
+   ```
+   python3 ~/.local/share/macropad/app/macropad-probe.py
+   ```
+   This only reads. It lists your pad's ID and its USB interfaces.
+
+2. **Start the capture** (it watches USB traffic; it never sends anything):
+   ```
+   cd ~/.local/share/macropad/app
+   sudo python3 macropad-capture.py
+   ```
+
+3. **In a second terminal**, open the vendor app with Wine:
+   ```
+   wine MINI_KEYBOARD.exe
+   ```
+
+4. In the vendor app, set **key 1 to the letter `a`** and click its save/apply button. Then set **each knob's turn left, press and turn right** to different letters, and save again.
+
+5. Go back to the first terminal and press **`Ctrl+C`**. You now have a file called `macropad-capture.txt`.
+
+6. **[Open an issue](https://github.com/Probler-Yt/MacroPad/issues)** with that file, your `macropad-probe.py` output, and a photo of your pad. That's genuinely all it takes to get your pad supported.
+
+---