Add a test suite, and fix the three dead-data bugs it found

There was no test file -- CLAUDE.md described the harness in prose and
referred to an "orphan-tag check" that did not exist. test.lua now stubs
the game globals and exercises the real engine, database and catalog tab
builders. It found three bugs on its first run:

* four_kind was the only theme in the catalog that could never be
  discovered. Theme discovery needs a giver and a wanter on two DIFFERENT
  fielded jokers, and The Family was its sole member -- so the Hands bar
  and the overall Progress bar could never reach 100%. DNA is the real
  enabler (copying a card is how you stack duplicate ranks, the only
  vanilla route to a reliable Four of a Kind), so it now gives the
  matching-hand tags as a pure enabler.

* hand_level was given by Space Joker and Burnt Joker and wanted by
  nobody, so it could never contribute to a score and its "want" tooltip
  text was unreachable. Nothing in vanilla rewards hand levels; the tag
  is dropped rather than faked.

* Invisible Joker had no tags at all, so it scored 0 against the entire
  game. Selling it duplicates one of your Jokers -- the same "stronger
  target, better payoff" logic Blueprint and Brainstorm already model --
  so it now wants copy_target.

The suite guards both directions of the tag contract (no orphan wants, no
dead gives), theme reachability, blurb widths, the inert-joker list, and
the card materialize fix from the previous commit.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

main.lua

@@ -267,7 +267,7 @@ local TAG_LABEL = {
     faces = 'face cards', retrig_scoring = 'played-card retriggers',
     retrig_held = 'held-card retriggers', hand_size = 'hand size',
     hands_up = 'extra hands', discards_up = 'discards',
-    probability = 'listed odds', money = 'money', hand_level = 'hand levels',
+    probability = 'listed odds', money = 'money',
     tarot_gen = 'Tarot cards', planet = 'Planet cards',
     spectral_gen = 'Spectral cards', gold_gen = 'Gold cards',
     stone_gen = 'Stone cards', enhance_gen = 'card enhancing',