Upgrade Relay to v20.1.1 and unify compiler config

Consolidate the two per-app relay configs (console and trust)
into a single multi-project relay.config.json at the repo root
with three projects: core, iam, and trust. Bump all relay
packages from v19 to v20.1.1 and move relay-compiler to the
root devDependencies. Replace per-workspace relay scripts with
a single root-level npm run relay command and update the
GNUmakefile, CI workflows, and docs accordingly.

Signed-off-by: Émile Ré <emile@getprobo.com>

turbo.json

@@ -16,9 +16,6 @@
     "dev": {
       "cache": false,
       "persistent": true
-    },
-    "relay": {
-      "cache": false
     }
   }
 }