frames,jar,passes: verifier-driven hardening from real jars

Proven by paranoid runs over lorep (17 classes, fully green),
LoVisual (4081 classes) and oc2r (1278 classes) with per-class
java -Xverify:all, each fix first reproduced as a red test:

- merge: Top absorbs instead of Top-wins (javac declares Top for
  slots unwritten on some inflow; precise types reject those edges).
  Regression: loop_head_keeps_top_for_loop_local.
- emit: collapse [Long|Double, Top] pairs on operand stacks
  (javac writes one entry; the pair is rejected). Regression:
  wide_stack_join_emits_single_entries.
- xfer ArrayLoad: push the wide pair, fixing lcmp underflow.
  Regression: array_load_wide_pushes_pair.
- xfer <init>: convert only the receiver's own allocation site
  instead of every Uninitialized (nested construction clobbered
  the outer object). Regression: nested_construction_keeps_outer.
- xfer ANewArray: array operands gain one dimension ([B] -> [[B)
  instead of an illegal L-wrap ([L[B;). Covered by the same test.
- jar load: duplicate class names (multi-release module-info
  twins) keep the first occurrence instead of crashing save.
  Test: duplicate_class_names_keep_first.
- strings/constants: skip methods past MAX_METHOD_INSNS (8000)
  so giants cannot overflow the 64KB writer ceiling. Tests:
  oversized_methods_are_skipped in both passes.
- merge errors now name both types being merged.

Also: em-dash removed repo-wide (724 spots, rule added to
todo.md), allow-lints only in tests (scratch example deleted),
code comments migrated to English in every file this change
touches.

crates/noxis-structure-check/src/rules.rs

@@ -1,10 +1,10 @@
 //! Project structure rules, invoked from every crate's `build.rs`.
 //!
 //! Rules apply to Rust code only, not to documentation:
-//! * every `.rs` file holds at most [`MAX_FILE_LINES`] *code* lines — blank
+//! * every `.rs` file holds at most [`MAX_FILE_LINES`] *code* lines - blank
 //!   lines and full-line comments (`//`, `///`, `//!`) are not counted;
 //! * every directory inside a crate's `src/`, `tests/` or `benches/` holds
-//!   at most [`MAX_DIR_FILES`] files — subdirectories are unlimited.
+//!   at most [`MAX_DIR_FILES`] files - subdirectories are unlimited.
 //!
 //! Deliberately excluded: `Cargo.lock`, `.gitignore`, `docs/`, the legacy
 //! `info/` tree, and crate roots (they always own `Cargo.toml` plus
@@ -34,13 +34,13 @@ const SKIPPED_DIRS: [&str; 2] = ["target", ".git"];
 ///
 /// # Panics
 ///
-/// Panics whenever a rule is violated — that is the point of the gate.
+/// Panics whenever a rule is violated - that is the point of the gate.
 pub fn check() {
     let manifest = manifest_dir();
     let mut violations = Vec::new();
 
     // `src/` is required; `tests/` and `benches/` are checked only when they
-    // exist — otherwise the line rule is bypassed by moving code into tests.
+    // exist - otherwise the line rule is bypassed by moving code into tests.
     // `docs/` stays out of the gate: the rules are about Rust code only.
     let roots = [
         manifest.join("src"),