claude@clouddev1
f239ca5ff4
Typing `--` to start an optional trailing flag (`--create-fk` on `add 1:n relationship`, `--cascade` on `drop column`, `--force-conversion` / `--dont-convert` on `change column`) made completion go empty: the trailing `--` turns the parse into a trailing-junk Mismatch, and the Mismatch arm of the completion expected-set resolution returned only `[EndOfInput]` — the skipped optional-flag expectations, carried in `tail_expected`, were dropped. completion_probe and expected_at_input now merge `tail_expected` into a Mismatch's expected set. `tail_expected` is empty for a genuine mid-command mismatch, so this only adds the outer shape's skipped trailing optionals — exactly the continuations the trailing `--` is starting to type. This also resolves the "wrong usage hint" symptom: with `--create-fk` offered as a candidate, the hint panel shows candidates instead of falling through to the parse-error usage block. Audit outcome (the requested scan): usage_key_for_input was verified correct for every multi-form command — add / drop / show, including the digit-led `add 1:n relationship` form — and is now regression-locked. The flag-completion fix covers the whole optional-trailing-flag class. 6 tests (3 flag-completion, 3 usage-key). 1131 passing.