Wait and both kinds of until loops; blocks run directly

Script runs are resumable threads saved with the game; Rhai is gone.

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

AGENTS.md

@@ -69,11 +69,10 @@ But before committing a completed change, the full local checks should pass unle
 ## Campaign scripting conventions
 
 - Mission scripts are **blocks** (`src/blocks.rs`), edited in the in-game block editor (`src/editor/blocks_ui.rs`); players never see code.
-- Blocks are translated into Rhai internally and run by `src/mscript.rs` inside the fixed simulation step (deterministic, co-op safe).
-- The Rust Rhai dependency must keep `no_time` enabled in `Cargo.toml` so the WASM output stays loadable by the macroquad JS bundle.
-- Rhai reserves `spawn`; the internal API uses `spawn_unit`.
+- The blocks are run directly by the interpreter in `src/mscript.rs` inside the fixed simulation step (deterministic, co-op safe); there is no scripting language underneath (Rhai was removed when "wait" came).
+- Script runs are threads (resumable after "wait", saved with the game); loops have a step budget per check so nothing can hang.
 - Per mission: special scripts (start, victory check, defeat check, clock) and triggers (`TriggerKind` in `src/campaign_doc.rs`).
-- New block kinds need: the `Block`/`Val` variant, `template`/`kind_name`, palette entry, checking, Rhai translation, the API function in `mscript.rs`, the editor fields in `blocks_ui.rs`, `blk.*` texts in every language file, and a test.
+- New block kinds need: the `Block`/`Val` variant, `template`/`kind_name`, palette entry, checking (`blocks::check`, `vars_set`), execution in `mscript.rs` (`exec`/`run_thread`/`eval`), nesting in `list_at` (mscript) and `list_mut` (blocks_ui) if it has a body, the editor fields in `blocks_ui.rs`, `blk.*` texts in every language file, and a test.
 - Side numbers: -1 any, 0 player, 1 heroes, 2 Mossgrim, 3 Lady Nightwell, 4 rival 3.
 - Unknown creature names, zones, triggers and unset variables are reported by `blocks::check`.
 - Reference: `docs/CAMPAIGN_EDITOR.md` and `docs/MISSION_SCRIPTING.md`.