rpi-loader-ota 0.2.0

Added

• apply, behind the feature of the same name: the other half of an
  update. It takes a validated bundle and a resident-fat volume and
  writes every entry where its path says, in an order the crate imposes
  rather than one the bundle chooses — ordinary files, then Raspberry Pi
  firmware, then config.txt, then the kernel. The kernel is last
  because while a board has one boot image that write is the commit, so
  everything that could fail has to have failed already.

  Nested destinations are created as needed, since a bundle can carry a
  path and write_file resolves a parent rather than making one.

• Entries the card already holds are read and not rewritten. The same
  function answers both halves of the question — before a write it
  decides whether to write at all, and after one it is the
  verification — so a skipped entry is checked exactly as strictly as a
  written one. A bundle carrying the Raspberry Pi firmware carries about
  3 MB of it, and that changes roughly once a year; on hardware, applying
  an unchanged bundle now costs 1055 ms and no card writes at all,
  against 3724 ms to write the same thing in full.

• Progress, which is how timing stays with the caller. Every method
  defaults to doing nothing and () implements the whole trait, so a
  caller names only what it wants. The boundaries separate the write from
  the read-back deliberately: those are not the same operation and do not
  have the same fix, so one figure covering both would hide which of them
  an improvement had touched.

• Checksum, the streaming form of checksum, for checking a file
  already on a card against a fixed scratch buffer rather than a second
  copy of it in memory.

Changed

• tests/ is no longer published. The suite builds its FAT32 volumes
  with mkfs.vfat and judges them with fsck.vfat, so it fails rather
  than skips without dosfstools — a suite that cannot run from the
  tarball it ships in says nothing about the crate.

Add it with cargo add rpi-loader-ota. The rpi-loader CLI
builds bundles in this format; a device installs one.