A photograph edited on two devices ends up with two `[version]` blocks in one
sidecar, both marked `default = 1`. Five of the thirty-eight sidecars in the
local cache are in that state right now.
`default_version` answered with the first `is_default` it met in map order,
and the map is keyed on uuid — so which device's work the photographer saw was
decided by which randomly minted uuid happened to sort lower. On
`IMG_20130625_0033` that is `0545c20a` over `679fe872`: a four-star rating from
the twenty-first of August standing in front of the one-star made on the
thirtieth, with nothing anywhere saying the newer judgement existed.
Resolved by `(revision, modified)` instead, which is the discriminator
`Version::merge` already uses — revision first so that a device with a skewed
clock cannot win by claiming a later timestamp (FR-NC-8), and the timestamp
only to break an exact tie.
This makes the reader pick the right one. It does not make the two converge:
the edit that lost is still in the file, and a device that holds disjoint work
— a crop here, an exposure change there — still only contributes one of them.
That is the next commit.
Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>