PM_K-1 CircuitPython: fix MemoryError + red/blue swap (from on-board test)

On hardware the app rendered, beeped and took input, then died with MemoryError at
the text Bitmap alloc — the two ~37KB base64 font strings stayed pinned in RAM. Move
the fonts to small binary files read at boot (font_m.bin / font_l.bin), drop the
base64 + binascii, and gc.collect() before each text bitmap. code.py 56KB -> 20KB and
RAM use drops ~37KB+. Also: cyan rendered as yellow (R/B swapped) -> MADCTL 0x40 -> 0x48.
Bundle + README updated to include the font blobs. (LED still needs the neopixel lib.)

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

build.sh

@@ -39,7 +39,7 @@ pathlib.Path("dist/pico-main.py").write_text(pathlib.Path("pico/main.py").read_t
 print("copied pico-main.py")
 import zipfile  # PM_K-1 CircuitPython drive bundle (download → unzip onto CIRCUITPY)
 with zipfile.ZipFile("dist/pm_k1_circuitpy.zip", "w", zipfile.ZIP_DEFLATED) as z:
-    for f in ("code.py", "programs.json", "README.md"):
+    for f in ("code.py", "programs.json", "font_m.bin", "font_l.bin", "README.md"):
         z.write("pico-cp/" + f, f)
 print("zipped pm_k1_circuitpy.zip")
 PY

pico-cp/README.md

@@ -15,9 +15,10 @@ same program‑string language as <https://metronome.varasys.io>.
 1. **Flash CircuitPython:** hold **BOOTSEL**, plug in, and drop the CircuitPython `.uf2` for your board
    onto the `RPI‑RP2` drive (<https://circuitpython.org/board/raspberry_pi_pico/> — or the Pico 2 / W
    build). It reboots and a **`CIRCUITPY`** drive appears.
-2. **Copy the files** onto `CIRCUITPY` (drag‑and‑drop — it's a normal drive now):
+2. **Copy everything from the bundle** onto `CIRCUITPY` (drag‑and‑drop — it's a normal drive now):
    - `code.py`  (this firmware — runs on boot)
    - `programs.json`  (your grooves)
+   - `font_m.bin`, `font_l.bin`  (the anti‑aliased fonts — kept as files to save RAM)
 3. It starts immediately. Editing `programs.json` (or re‑saving it from the editor) makes CircuitPython
    **auto‑reload** with the new tracks.
 
@@ -39,7 +40,7 @@ Each `prog` is a program string from the web editor. Add/replace entries and sav
 
 ## Calibration (flip flags at the top of `code.py`)
 
-- **Red/blue swapped:** change `MADCTL = 0x40` to `0x48`.
+- **Red/blue swapped:** flip `MADCTL` between `0x48` (default) and `0x40`.
 - **Colours look negative:** toggle `INVERT_COLORS`.
 - **Taps land wrong:** set `TOUCH_DEBUG = True`, watch the serial output, then set
   `TOUCH_SWAP_XY` / `TOUCH_INVERT_X` / `TOUCH_INVERT_Y`.