CycloneStore split precedent (SP21) — lift three helpers from
scheduler.py + api.py into one module. Both callers will switch
to this in Task 6. The new package also defines HandleResult
and the HANDLERS registry; handle_999 / handle_ta1 / handle_277ca
/ handle_835 fill in over Tasks 2-5.
The registry is lazy + best-effort: register_handlers() catches
broad Exception so a partial-modification SyntaxError in one
in-flight handler module can't break scheduler or API import.
11 tests added; existing suite unchanged (1 failed + 2 errors
pre-existing in test_provider_extended_response.py are not
introduced by this commit).
Nora