Small-screen patching, Windows touch and BLE MIDI, C3 handheld controller

[willbearfruits]

Draft, opened so CI builds the Windows app for a test on the ROG Ally.

Patching on a small screen

• A module picker (+ ADD, A, or "Add a module..." in the menus): large tiles by family, filter by typing, d-pad and bumpers on a pad. The module goes after the selected one, or at the end of the chain, with the cables moved over.
• On the Board, a + between each pair of pedals puts a new pedal there.
• Module and pedal menus: add before or after, move earlier or later, remove and keep the chain connected. Each is one undo step; stereo pairs stay paired. The logic is in src/audio/ChainEdit.*, with two new tests.
• Touch: a tap on a knob opens a large slider (exact value, steps, reset, type, fine). A taller header with finger-sized buttons, MUTE, UNDO and REDO on screen. A held finger on a plate or pedal now opens its menu (before, the drag it started blocked the long press).

Windows

• JUCE's WinRT MIDI backend, so paired Bluetooth LE MIDI devices show up (SIGNALPATCH_WINDOWS_BLE_MIDI, on by default).
• Windows' own press-and-hold is turned off for the window, so a press arrives at once (src/v2/PlatformWindow.cpp).
• The first start on a screen smaller than the default window is maximised.

These Windows-only parts have not been compiled before this CI run.

C3 handheld controller

• Firmware for an ESP32-C3 SuperMini with a 0.42" OLED, encoder, three pots, three buttons, expression jack and MPU-6050, over BLE MIDI (controller/c3-oled).
• Protocol additions in docs/CONTROLLER.md: labels and values, mute flag, model and firmware in the hello, settings over SysEx.
• A CONTROLLER page: assign each control (tap a knob, pick from a list, or an app action in every patch), live values, the controller's settings. Pots take over a knob only once they pass its value; mappings follow a channel change.
• A printable case in controller/c3-oled/enclosure.

Tested

• 59 engine tests pass, also under ASan and UBSan.
• The touch flows were driven with the new SIGNALPATCH_UI_SCRIPT hook at the Ally's size (1920 x 1080 at 150 %). The CONTROLLER page was run against controller/tools/fakec3.c, which plays the C3 on an ALSA port.
• Firmware: pio run -e c3 builds; 72 host tests pass.
• Case: the enclosure build ends DONE (fit, margins, meshes).

Not tested

• Anything on Windows, a real touch screen, or Bluetooth.
• The firmware on a board, and the case printed.

🤖 Generated with Claude Code