Spec M15 — bundled standard library, `#include <name>`, `#embed`

Goal: the mc binary serves everything a program or a taught compiler needs; no repository checkout.

Bundle #

tools/bundle.list: manifest, one name<TAB>path per line, sorted by name. Names: sys, sys_svc, io, prelude, user_default, backend_arm64, ... for lib/*.mc, and mc/core, mc/arena, mc/macho, ... for every src/*.mc that src/core.mc includes (NOT bundle_data.mc).
tools/bundle.mc (an mc program): reads the manifest, compresses each file with src/lz.mc, writes src/bundle_data.mc: u8 bundle_blob[] = { ... } (decimal bytes, 24 per line) plus flat index arrays uptr bundle_name[], i64 bundle_off[], bundle_csize[], bundle_rsize[] and #define BUNDLE_COUNT N. Byte-for-byte reproducible (make bundle twice -> cmp identical).
src/lz.mc: LZ77 with a 64 KiB window, greedy longest match, tokens literal run / (len,dist); lz_deflate(src, n, dst) -> csize, lz_inflate(src, n, dst, rsize). Deterministic, ~150 lines. Round-trip test on every file of the manifest and on random data.
src/bundle.mc: bundle_find(name) -> index or -1, bundle_read(i) -> uptr (inflated, cached). Special name mc/bundle_data: regenerated on the fly from the in-memory blob (the bundle cannot contain itself) so <mc/core> is complete for a taught compiler.

#include <name> -> bundle_find; pushed as file <name> (that is what error messages show). Unknown name -> unknown bundled include: <name> listing nothing else.
#include "x" search order: includer directory, then [include].paths from the TOML (M14), in order.
src/core.mc keeps #include "..." between compiler modules (they are inside the bundle by name and the lexer resolves relative includes among bundled files by name).

#embed name "path" [lz] (directive at top level): declares u8 name[] with the file bytes (or the LZ stream when lz is given) and #define name_size N (bytes in the array) and name_raw N (original size). Path resolves like #include "x". Programs decompress with <lz>: lz_inflate(name, name_size, buf, name_raw).
Limits: file <= 16 MiB; error otherwise.

mc build with [compiler].modules builds the taught compiler from #include <mc/core> + modules, no repository paths. examples/api/mc-api.mc switches to #include <mc/core>.

tests/070-embed.mc (embed a small text file, print it), tests/071-embed-lz.mc (round trip), tests/072-include-bundle.mc (#include <sys>/<prelude>; runs).
Empty-directory test (scripts/check-standalone.sh, in make check): copy build/mc-exe to a temp dir, compile a program using <sys> and <prelude>, build a taught compiler from <mc/core> + a syntax module, use it — all without the repository.
make bundle reproducible; make check green; fixed point holds (the bundle is part of src/).
Size report: mc-exe before/after; blob compressed vs raw.