- evaluator.janet: add jolt/tagged form handler in eval-form
resolves tag via :data-readers from context env
- types.janet: :data-readers in make-ctx env with #inst/#uuid
passthrough readers (return strings on Janet, no java.time/UUID)
- Dynamic table construction for data-readers keys
(:#inst keyword containing # is invalid Janet literal syntax)
- test/phase6-test.janet: 4 test sections (28-31)
#inst, #uuid, #? conditionals, #?@ splicing — all pass
- 315 ok, 2 fail (pre-existing, unchanged)
