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.
Final 0102 sub-step. fix-0102c landed resolveBareCallee and routed the
primary call path + parameter target typing through it, leaving four other
bare-name consumer sites on the old first-wins path. Route the SAME resolver
through all four, gated exactly as the call path (plain top-level identifier,
no scope-mangle / UFCS alias / local shadow; act on .func / .ambiguous, fall
through on .none so single-author / local / std / qualified / foreign-single
resolution is byte-for-byte unchanged):
1. Default-argument expansion (expandCallDefaults): omitted trailing args
fill from the RESOLVED author's defaults, not the winner's.
2. Function-value conversion (closure(fn) and the bare-fn-as-value func_ref /
fn-ptr / closure-coercion path): captures the resolved author's FuncId.
3. Free-function UFCS (recv.fn() -> fn(recv, ...)): dispatches the resolved
author for the receiver's source.
4. Comptime #run of a bare call: lowerMainAndComptime now sets
current_source_file per decl, so a `NAME :: #run f()` in an imported
module resolves f from THAT module's flat imports (own-author wins) instead
of the main file's perspective (which made it spuriously ambiguous).
Regression tests: examples/0730-0734 (default-arg, closure+fn-value, UFCS,
comptime #run, UFCS-ambiguity), each fails on pre-fix code and passes after.
issues/0102-flat-import-same-signature-collision.md written RESOLVED with the
4-sub-step root cause and regression-test paths.
