allocators/fs/process/socket/log/trace/test move under modules/std/
(allocators.sx becomes std/mem.sx; the Allocator protocol moves into
the std.sx prelude, impls stay in mem.sx). New std/xml.sx holds
xml_escape as xml.escape. std.sx gains the carried namespace tail —
flat-importing std.sx now also provides mem./xml./log. — with the
remaining modules (fs/process/socket/json/cli/hash/test) deferred from
the tail until the global last-wins maps are fully own-wins (pulling
them into every closure collides bare names corpus-wide; they stay
direct imports: modules/std/fs.sx etc.). log.sx's internal emit
renamed log_emit (it clobbered consumer fns named emit program-wide).
bundle.sx uses xml.escape via the carried alias. Consumer import paths
swept mechanically; .ir snapshots recaptured for the larger std
closure. m3te + game build unchanged.
Foundation milestone close — the minimal exit-code / --json contract
`dist` relies on, in pure sx (no compiler change).
- EX_OK (0) / EX_USAGE (64, sysexits.h) / EX_UNAVAILABLE (70) named
constants in std.cli.
- exit_ok() / exit_usage() terminators routing through the canonical
process.exit(code: u8) — removes the hand-rolled cli_bail_exit `_exit`
binding; the unsupported-platform path now uses proc.exit(EX_UNAVAILABLE).
- --json read is parsed.json (already parsed by F3.2); documented as the
detection point with a stdout-pure / stderr-human convention.
- examples/0718-modules-cli-exit-json.sx exercises the contract: json true
with --json / false without, EX_USAGE == 64, and a usage path that exits
64 via exit_usage() (expected .exit = 64).
- readme.md gains a std.cli command-line-interface subsection.
