Melodee 1.3.3

Melodee 1.3.3 removes the last clock change at 360 MHz.

1.3.2 made 360 MHz the default, but still retuned the system clock once: on the first
start after updating from a 1.3.0 or 1.3.1 that ran at 320 MHz, because the clock survives
the update's restart. On the FM-1s that cannot take a retune (1.3.0 and 1.3.1 left them in
UBOOT behind a black screen), that is the step that fails.

• At 360 MHz Melodee never touches the clock. A 320 MHz left by an update stays until the
  next power-off; the FM-1 starts at 360 MHz after that.
• Switching OVERCLOCK to 360 MHz applies at the next power-on and says
  360 MHZ AT POWER-ON. Switching to 320 MHz still offers a restart.
• Everything from 1.3.2 stays: 360 MHz by default, the clock guard (CPU FAULT /
  PLL FAULT: 360 MHZ, 360 ONLY), and the retune only with a verified watchdog.

If an FM-1 is stuck in UBOOT, restore it with the recovery tool from these downloads
(fm1-recover --info, then a .fwsc backup run, then --write; see RECOVERY.md in the
archive) or with M-VAVE's updater, then install 1.3.3. Running the recovery tool once
without --write first saves a backup that shows why the FM-1 stopped; please attach it
to a bug report.

Firmware downloads include Standard (dual-core) and Single core variants.
BUILD_INFO.json records the source commit and native executable smoke tests;
SHA256SUMS covers all release assets.