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.
resolveForwardIdentifierAliases now resolves a forward alias A :: B against
B AS SEEN FROM A's own source via selectNominalLeaf (E1's source-keyed
nominal leaf over type_aliases_by_source / moduleTypeAuthor), never the
global type_alias_map / global findByName. The already-resolved guard is
per-source (aliasResolvedInSource). .pending routes back into the fixpoint;
.undeclared / .not_visible leave A unwritten (no global last-wins leak).
This is the sequencing pin before E2: a global fixpoint binds A to a
same-name B authored by a different module (e.g. a namespaced import that
pollutes the global alias map last-wins), re-opening 0105 one layer down
once shadows register. Writes stay on the unified putTypeAlias helper (E1
no-drift invariant); the single graph-walk in resolver.zig is untouched.
Regression: examples/0750-modules-forward-alias-source-aware — a forward
alias A :: B with main's own B :: u64 and a namespaced same-name B :: u8;
A must bind main's u64 (300), not the global last-wins u8 (44).
