Fix errors caused by the switch to VESC 7.00.

[mikeller]

Compatibility fix release for VESC firmware 7.00.

Changes

Fix: Cold-boot dark display (I2C first-message bug)

On VESC firmware 7.00, the first i2c-tx-rx call after i2c-start on a cold boot is silently dropped and never reaches the I2C device. The HT16K33 display controller's oscillator-enable command (0x21) was never delivered, leaving the oscillator stopped and the display permanently dark.

Workaround: send the oscillator-enable command twice in peripherals_setup; the first write is sacrificial (absorbed by the bug), the second reaches the controller.

Fix: Package crash on second and subsequent boots (move-to-flash → @const-start)

VESC 7.00 re-evaluates package source on every boot but preserves the flash heap from the previous session. The previous move-to-flash calls conflicted with the already-populated flash heap and caused an abort before any threads were spawned.

Fix: replaced all move-to-flash calls with the @const-start / @const-end block syntax, which is the correct mechanism for VESC 7.00.

Docs

• README.md: version bump to 1.3.1, added "What's New in 1.3.1" section, updated firmware requirement to 7.00.
• DEVELOPMENT.md: new "VESC 7.00 Compatibility" section documenting the const-block layout strategy (rules a–f) and the I2C first-message bug workaround.