refactor: split org-drill-entry-status classifier from its predicates

Two extractions out of the 58-line cond:

- org-drill--entry-empty-and-not-empty-friendly-p: encapsulates the
  ugly nested predicate that means 'body is empty AND the card
  type doesn't opt in to empty bodies'.  Used to be 5 inlined
  lines including a let* and an alist lookup.
- org-drill--classify-status: takes the precomputed DUE and
  LAST-INT and walks the cond.  The decision tree is now a
  flat sequence of one-line clauses.

org-drill-entry-status itself drops to 8 lines and reads as
'compute the inputs, classify, return triple'.  The :failed branch
also uses org-drill--quality-failed-p instead of inlining the
threshold check.

0 files changed, 0 insertions, 0 deletions