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.
Two coupled capabilities on the road to the std restructure
(current/PLAN-STDLIB.md, issue 0114):
1. alias.Type.method() / alias.Type as a call head, alias.CONST, and
alias.Enum.variant now resolve — previously only alias.fn() and
type-position alias.Type worked. objectIsValue treats an
alias-rooted field_access as a type head; the call path strips the
alias to the existing Type.method machinery; lowerFieldAccess
resolves alias.CONST pinned to the target module and alias.Enum.x
as a typed enum literal; resolveTypeWithBindings resolves qualified
type_exprs pinned to the target.
2. The carry rule: namespaceAliasTarget resolves an alias from the
file's own edges first, then from DIRECT flat imports (one level),
diagnosing two distinct carried targets as ambiguous. All qualified
shapes work through a carried alias — the std.sx namespace tail
(mem.GPA.init() etc.) is now expressible.
Regression: examples/0831-modules-namespace-alias-carry.sx (direct +
carried, all seven shapes).
