feat: generator interpreter for Python that waits for the player (Ren'Py)

Python containing renpy.input, narrator("..."), character calls, renpy.say,
renpy.pause, renpy.display_menu, renpy.with_statement or renpy.call_screen now
runs through loops, try, functions, methods and expressions.

Player
- python.ts: execG/evalG/callG run only the code that may wait (mayBlock);
  everything else stays on the synchronous fast path. A waiting call returns a
  BlockingCall; outside the generator interpreter it is an explicit error. The
  interpreter scope is set aside while the player decides
- engine: drives the generator and answers requests (dialogue, text input with
  length/allow/exclude, pause, choice menu, transition, call screen)
- renpy.show/hide/scene, transitions and transforms as Python values,
  Character(...) objects, Borders, set_tag_attributes

Converter
- blocking_names() lists game functions that may wait, transitively, and ships
  them as game.json "blocking"; character calls are allowed
- hide screen of an unknown screen is harmless; images defined by a parenthesised
  expression are supported

Hooked now passes the strict compatibility check (with Tomie and Twisted-Thoughts).
Tests: waiting.py fixture run through the generator interpreter; blocking-name analysis.

Co-Authored-By: Claude Sonnet 5.5 <noreply@anthropic.com>

frontend/src/player/player.css

@@ -360,3 +360,8 @@
 .pg-sbar:not(.pg-svbar) .pg-sbar-fill { height: 100%; }
 .pg-sadd { pointer-events: none; }
 .pg-sviewport { scrollbar-width: thin; }
+
+/* --- renpy.input / renpy.display_menu ----------------------------------------------- */
+.pg-input { display: flex; flex-direction: column; gap: 12px; align-items: center; pointer-events: auto; }
+.pg-input input { font: inherit; font-size: var(--pg-font, 24px); padding: 6px 10px; min-width: 40%; }
+.pg-caption { color: var(--pg-text, #fff); opacity: 0.8; text-align: center; padding: 4px 0; }