`PowerStore::get` ended `Ok(row.and_then(|s| Wanted::parse(&s)))`, so a
row holding an unparseable value collapsed into the same `Ok(None)` as
no row at all. Its doc comment stated the narrower case as the whole one
("`None` when the agent has no row yet"), which is what kept the gap
invisible.
The damage is not that a caller reads the wrong value. `get_or_seed`
takes `None` to mean "never seeded" and writes
`Wanted::from_running(running)` — so a corrupted row silently
**overwrote itself** with whatever the container happened to be doing at
that moment, which is precisely the inference an authoritative intent
store exists to prevent. Its own comment says the DB is authoritative
once seeded.
The error arm was already in the signature; this makes it reachable.
Every caller already handles `Result`: the two `get_or_seed` paths
propagate, so a corrupt row now fails that agent's boot reconcile
instead of erasing itself, and `workers::wanted` already skips an agent
whose intent could not be read.
The second test is the one that matters — it asserts the row still holds
its original bytes afterwards, because the overwrite, not the read, was
the bug. Both tests carry a valid and an absent row alongside, so
neither can pass by breaking `get` for everything.
Found by argus reviewing #3891, which reads this store but does not
write it.
978e66790c