fix: body-local #run of an unbridged shape fails loudly instead of silent garbage (issue 0182)

The body-local #run fold in emitCall was effectively dead (gated on
args.len==0, but the __ct comptime wrapper always carries the implicit
*Context arg), so every body-local #run fell through to a RUNTIME call:
bridgeable shapes lucked into the right value; an unbridgeable shape
(e.g. [2][]i64) ran over --- storage -> garbage, exit 0, no diagnostic.

Fold any is_comptime callee (gated !enclosing.is_comptime so nested
metatype calls in a comptime wrapper's dead body aren't folded). On a
tryEval bail, distinguish a BRIDGE bail (result can't regToValue-
materialize -> error: comptime init of 'X' failed: <reason> +
comptime_failed, build fails, symmetric with the global #run path) from
an EXECUTION bail (VM can't run the body, e.g. NaN/extern -> runtime
fallthrough, preserving types/0150), via comptime_vm.last_bail_was_bridge
(reset at tryEval entry, set only at regToValue). The const name is
threaded onto the wrapper (comptime_display_name) so the diagnostic reads
the source name, not __ct_N.

Regressions: diagnostics/1204 (negative), comptime/0645 (positive).
Verified by 3 adversarial reviews, suite 801/0.

src/ir/lower/stmt.zig

@@ -478,6 +478,13 @@ pub fn lowerConstDecl(self: *Lowering, cd: *const ast.ConstDecl) void {
         return;
     }
 
+    // For a body-local `#run` const (`L :: #run f()`), record the const NAME so
+    // the `__ct` wrapper carries it as a display name — a comptime-init failure
+    // then reports `comptime init of 'L' failed` instead of `__ct_N` (issue 0182).
+    const saved_ct_name = self.comptime_const_name;
+    if (cd.value.data == .comptime_expr) self.comptime_const_name = cd.name;
+    defer self.comptime_const_name = saved_ct_name;
+
     const ref = self.lowerExpr(cd.value);
     // If there's an explicit type annotation, use it. Otherwise, infer from the expression.
     const ty = if (cd.type_annotation) |ta|