Rename mesh-control -> mesh-controller, substrate -> foundation

One name per thing, per the HQ glossary: the module/container/image/binary/repo
becomes mesh-controller, the seat the-controller, and the store+broker pair the
foundation (embedded base bundles, default template and example lock renamed with
their go:embed directives). No behaviour change — a pure vocabulary rename.

Claude-Session: https://claude.ai/code/session_01D6qtiYU3P9jk3pnAXyAFyx

modules/model-usage/index.ts

@@ -1,4 +1,4 @@
-// model-usage's entrypoint — the usage context store's consumer (novox/hq ADR 0054). mesh-control is
+// model-usage's entrypoint — the usage context store's consumer (novox/hq ADR 0054). mesh-controller is
 // a CLI and cannot consume events, so the store that keeps the latest usage reading is a MODULE: it
 // subscribes to `module.*.usage.*` and upserts each row. Like the audit-logger, the on(...) IS the
 // whole handshake — the runtime imports this once the broker is bound, and every usage event any