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

src/lifecycle/place.ts

@@ -5,7 +5,7 @@
  * the thing it exists to test did not exist (novox/hq 03-DESIGN/00-as-is/11-the-lab.md). Tier
  * 0 now does, so this is the seam where the lab acquires a consumer.
  *
- * Only `host` is placeable. Everything else in the placement vocabulary — the substrate, a
+ * Only `host` is placeable. Everything else in the placement vocabulary — the foundation, a
  * control plane, a forge — is still refused by name rather than ignored, because a scenario
  * that declares something and raises without it is the fault this lab was built to catch
  * (novox/hq 04-ISSUES/003).
@@ -515,7 +515,7 @@ export async function loadHeldImages(
       throw new Error(
         `${requested} is not on this workstation, so there is nothing to hand the machines.\n` +
           `  It is one of the mesh's own images and exists in no registry — nothing can pull it.\n` +
-          `  Build it first (mesh-control's \`make image …\`, or scripts/build-module-runtime.sh).`,
+          `  Build it first (mesh-controller's \`make image …\`, or scripts/build-module-runtime.sh).`,
       );
     }
   }