Surface rename of the signed integer family: s1..s64 become i1..i64
(u1..u64, usize, isize unchanged). 'string' keeps the s-prefix arm in
name classification; width parsing moves to the i-prefix arm next to
isize.
Internal TypeId tags follow the surface (.s8/.s16/.s32/.s64 ->
.i8/.i16/.i32/.i64), as do mono-key mangle fragments (ptr_i64,
tu_i64_bool) and all display/diagnostic formatting (i{d}).
Migrated in the same sweep: stdlib + examples + issue repros + FFI C
companions (shared symbol names like ffi_id_i64), expected
stdout/stderr/ir snapshots, specs.md, readme.md, CLAUDE.md/AGENTS.md,
implementation_plan.md, docs/, issue writeups. Vendored stb_image and
historical flow state left untouched.
zig build test: 426/426; examples suite: 595/595.
Route the Lowering-side bare type leaf through the source-keyed caches (E0):
nominal author via collectVisibleAuthors(.user_bare_flat) + alias via
type_aliases_by_source, instead of the global findByName first-match. The
binding-free resolveAstType path + registration sites stay on the global
compat readers (move later). Single-author resolution byte-identical (no
shadows yet). Folded req #1: a namespaced-only import's const is no longer
bare-visible in array-dim/comptime-scalar position. Adds regression 0742
(ns-only bare const) and 0210 (generics/Vector/type-fn stay legacy).
Salvaged from a worker killed at the wall before commit; manager verified
the gate at ground truth (zig build test exit 0; run_examples 479/0 with
0210+0742 ok, prior 477 byte-identical; m3te ios-sim exit 0; folded fix
confirmed fail-before on master 7ffc0c1 exit 0 / pass-after exit 1).
