tooltips app TDD spike + kit bag refactor to .tt

- New apps.tooltips: TooltipContent model, {% tooltip data %} inclusion
  tag, _tooltip.html partial with .tt/.tt-title/.tt-description etc.
  class contract; 34 tests green
- Kit bag panel (_kit_bag_panel.html): .token-tooltip → .tt + child
  class renames (tt-title, tt-description, tt-shoptalk, tt-expiry)
- game-kit.js attachTooltip: .token-tooltip → .tt selector
- SCSS: .tt added alongside .token-tooltip for display:none default +
  hover rules in _wallet-tokens.scss and _game-kit.scss

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

src/functional_tests/test_game_kit.py

@@ -105,7 +105,7 @@ class GameKitTest(FunctionalTest):
             "arguments[0].dispatchEvent(new Event('mouseenter'))", deck_el
         )
         tooltip = self.browser.find_element(
-            By.CSS_SELECTOR, "#id_kit_bag_dialog .kit-bag-deck .token-tooltip"
+            By.CSS_SELECTOR, "#id_kit_bag_dialog .kit-bag-deck .tt"
         )
         self.wait_for(lambda: self.assertTrue(tooltip.is_displayed()))
         text = tooltip.text