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/anthropic-manager/test/sealedbox.test.ts

@@ -5,7 +5,7 @@ import { generateKeyPairSync } from "node:crypto";
 import { seal } from "../sealedbox.ts";
 
 // The definitive proof that this seal interoperates with Go's box.OpenAnonymous (the host's Unseal
-// and mesh-control's secrets.Seal/Open) is a cross-language test in mesh-control
+// and mesh-controller's secrets.Seal/Open) is a cross-language test in mesh-controller
 // (internal/secrets/sealedbox_xcheck_test.go), which opens a fixture this module's seal() produced.
 // These tests hold the TypeScript side: the output has the crypto_box_seal shape, and it is
 // randomised so a rotation that changed nothing looks nothing like one that changed everything.