jolt build: compile an app to a standalone binary (Phase 4 stages 1-2)

Restores the standalone-binary capability the Janet host had. `bin/joltc build
-m NS -o OUT` AOT-compiles an app into a single self-contained executable — the
whole runtime, clojure.core, stdlib and compiler embedded, no Chez install or
jolt source needed at runtime.

Pipeline (host/chez/build.ss, host primitive jolt.host/build-binary driven by
jolt.main's build command): resolve deps, load the entry namespace recording the
app namespaces in dependency order, re-emit each to Scheme, textually inline the
cli.ss runtime load sequence into one flat source + the app + a launcher, then
compile-file -> make-boot-file -> embed the boot as C bytes -> cc-link against
libkernel.a.

Two non-obvious bits: the compile pass runs in a fresh Chez, not the loaded
runtime (regex.ss shadows top-level `error`, which otherwise bakes a broken
reference into the boot); and the launcher installs scheme-start rather than
running -main at top level, since boot top-level forms execute during heap build
before argv is set, so args only reach -main through scheme-start.

Loader: a require of an in-memory namespace with no source file now no-ops, so
AOT'd app namespaces satisfy require in a built binary.

Mode flags (--opt/--dev, default release) are plumbed; the optimization passes
they gate come in a later stage. RFC 0007 has the design. Gated by `make
buildsmoke`.

Makefile

@@ -4,7 +4,7 @@
 # build step. `make test` is the full gate. `make remint` rebuilds the seed after a
 # source change.
 
-.PHONY: test ci values corpus unit smoke selfhost sci certify ffi transient remint
+.PHONY: test ci values corpus unit smoke buildsmoke selfhost sci certify ffi transient remint
 
 # Full gate (dev machine). Includes the self-host byte-fixpoint, which only holds
 # on the same Chez that minted the seed.
@@ -15,7 +15,7 @@ test: selfhost ci
 # lockfile) — it RUNS correctly on any Chez, but `selfhost` rebuilds it and a
 # different Chez version may emit byte-different (gensym/order) output, so the
 # byte-fixpoint is a dev-machine check, not a CI one (jolt-8479).
-ci: values corpus unit smoke sci ffi transient certify
+ci: values corpus unit smoke buildsmoke sci ffi transient certify
 	@echo "OK: CI gates passed"
 
 # Self-host fixpoint: bootstrap.ss rebuild == checked-in seed.
@@ -38,6 +38,10 @@ unit:
 smoke:
 	@sh host/chez/smoke.sh
 
+# `jolt build` produces a working standalone binary.
+buildsmoke:
+	@sh host/chez/build-smoke.sh
+
 # SCI conformance: load borkdude/sci's source through joltc (floor-gated).
 sci:
 	@chez --script host/chez/run-sci.ss