* test(fuzz): structured CLI/Maestro generators that reach command validation and assert error codes (#1781 B2)
* test(fuzz): pin the rediscovered #1433 excess-positional case and keep numeric flag samples inside their range
* style: apply oxfmt to the new fuzz modules
* perf(fuzz): derive the CLI validation surface lazily so unrelated harness paths keep their startup
* test(fuzz): resolve validation generators in the run path so corpus replay keeps its small module graph
* test(fuzz): weight the CLI budget toward command validation, pin the finite classes as seeds, guard lazy surface derivation
* docs(testing): describe the validation lane's layer split, seed-pinned classes, and PR-time gates
* refactor(fuzz): split the validation generator into CLI and Maestro modules, mirrored in tests
* refactor(fuzz): collapse the flag-shaped mutation classes and seed literals, derive class coverage from declarations
* fix(fuzz): hash every case-generation module in configHash, guarded by an import-closure test
* test(fuzz): assert CLI command and flag-key coverage against the registry, and close the six gaps it found
Michał Pierzchała