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.
attempt-6: address Adi's two in-scope findings (#3 deferred to E6).
#1 E4-own-author-type-arg (silent-wrong): the bare-TYPE gate returned
`.proceed` for the querying source's OWN author, so the non-leaf sites
(reflection / type-arg / array-literal / type-value / match arm) dropped it
and re-resolved a same-name flat import via global `findByName`. headTypeGate
now resolves the own author to ITS per-source TypeId (mirroring
selectNominalLeaf's own-wins, 0754); the type-as-value and type-match sites,
which only consumed the poison bit and re-resolved globally, now route through
the gate and use the `.resolved` author. size_of(Widget) with an own + imported
Widget now yields main's own size, not the import's.
#2 E4-type-fn-head-ambiguity (silent-wrong): headFnLeak only checked
isNameVisible, so two flat same-name type-returning functions both reported
"visible" and one was silently instantiated. It now diagnoses >=2 distinct
direct flat type-fn authors (no own author) as ambiguous before the
isNameVisible short-circuit, consistent with the parameterized struct /
protocol heads and the leaf (0755/0767). Own / single / diamond-collapse
type-fn heads still resolve.
Regressions: 0768 (own-wins at every non-leaf bare-type site, fail-before
reflection=16 -> pass-after 8) and 0769 (two flat Make type-fns -> ambiguity
diagnostic exit 1). README: own-wins + type-fn-head ambiguity at every bare-type
site.
