Three inline findings and one of the two suppressed. The other suppressed
one — that the hand-off's delete is still a TOCTOU — is the cross-process
guarantee, decided against for this PR and tracked as #2082.
**My convergence tests did not converge anything.** The reviewer caught that
the "two stores racing" tests cannot race: `serialize` keys its queue on the
resolved path *process-wide*, which I made it do in the previous commit
precisely so two instances would take turns. So the tests passed by
serialization while their names and comments claimed they were exercising
the optimistic retry, and the retry's successful path had no coverage at all.
A fix I was pleased with silently disabled the tests written to prove it
worked.
Split in two now, both honest about what they drive:
- `in-process mutations are serialized per path` keeps the multi-instance
cases, which pin a real property — it is what makes the in-process case
correct *without* relying on the retry.
- `cross-process convergence` injects one external write between the store's
write and its verifying read, via raw `fs` so it bypasses the queue the way
another process would. The surviving entry can only be explained by the
re-apply, so these pin the mechanism rather than the outcome. Covers a
set, a delete, and the encrypted path where every attempt re-derives.
**A well-formed envelope is not an openable one.** `readOnDiskEncryption`
classified by structure alone, so a wrong or unset `MCP_INSPECTOR_SECRET_KEY`
produced the quiet, healthy "Encrypted file" footer for a file whose every
`get` returns `null` and every `set` is refused — the exact state the
unreadable footer promises to warn about. It now authenticates: decrypt and
discard, costing one scrypt derivation (~23ms) per descriptor build, once per
`/api/config`. A test asserted the old behavior and has been rewritten; the
comment on it explains why "describable" has to mean *accurately* describable.
**The copy button's `aria-label` was eating the warning.** `aria-label`
replaces descendant text, so a screen-reader user heard "Copy secrets file
path …" and never heard "Plaintext file" — the one sentence that should
change their mind about typing a secret. The status now leads the accessible
name and the path follows, which also keeps the name a superset of the
visible text (WCAG 2.5.3).
**The spec still described the pre-#1950 invariant** in its migration
bullets: every plaintext secret lifted into the keychain and removed from
`mcp.json`, with only `KeychainUnavailableError` named. Both bullets now
describe the selected store, the durability gate that withholds the disk
delete for a session-scoped store, the strict read behind the store-wins
lookup, and `SecretStoreUnavailableError` as the family the handler catches.
Full `npm run ci` green, including the per-file ≥90 gate — the new validator
and retry branches needed six more cases to clear it.
Signed-off-by: cliffhall <cliff@futurescale.com>