Local blob store under src/store/, the first real consumer of std.hash.
Objects are addressed by lowercase-hex SHA-256: the digest is the storage
key and bytes live at <root>/objects/<sha256>.
- put_bytes / put_file compute the digest via std.hash, write to a
staging file, then atomically rename into objects/<sha256>. The rename
is the only step that publishes, so an interrupted/failed write never
leaves a torn object at the final path.
- Dedup: an already-published object short-circuits without re-staging.
- stage_write/stage_copy + publish expose the two phases for the test.
tests/store_content_addressed.sx asserts the storage key equals std.hash,
an independent `shasum -a 256`, and the pinned SHA-256("abc") vector;
that dedup stores one object and never rewrites it; that a staged write
is invisible until publish and a failed publish leaves no object; and
that put_file round-trips bytes. Gate: make build + make test both green.
Stand up the foundation every later step depends on:
- Source layout: src/, src/infra/, tests/, examples/ (.gitkeep markers).
- Makefile: `build` compiles the smoke program via $SX, `test` runs the
runner over tests/**/*.sx, `publish-example` placeholder (real in P3.4).
Compiler located via `SX ?= /Users/agra/projects/sx/zig-out/bin/sx`.
- tests/run.sh: POSIX-sh runner; discovers tests/**/*.sx, runs each via
`$SX run`, prints ok/FAIL, exits 0 only when all pass (errors on zero
tests so the gate is never silently empty).
- tests/smoke.sx: passing smoke test importing modules/std.sx — proves
toolchain wiring end-to-end (std resolves via the binary's own location).
- .gitignore: ignore build/ artifacts.
