No inline assembly, no global register variables; libavr does the
datasheet work. The device speaks primitives — flash read/page-program,
EEPROM read/write, fuse read, info block, EEPROM-resident activation
timeout, hand-over — and verify, erase, reset-vector surgery, and
timeout configuration live in the host tool. 490 B on the ATtiny13A,
510 B on the ATtiny85, 484 B on the ATmega328P, each linked into the
top 512 bytes of flash; per-chip size tests gate all three.
Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>
