fix(core): inner @relayauth/sdk dep stuck at caret 0.1.0

@relayauth/core@0.2.0 was published with "@relayauth/sdk": "^0.1.0"
in its dependency list — a stale caret range from before the 0.2.x
line. npm dutifully installs the latest matching version (0.1.9) into
a nested node_modules/@relayauth/core/node_modules/@relayauth/sdk,
so downstream consumers end up with both 0.2.0 (top-level) and 0.1.9
(nested under core) at the same time.

Nothing routes through the nested copy from cloud today — every
cloud package resolves the top-level 0.2.0 directly — but it is
dead weight, wasted install size, and a real bug if any future code
path reaches @relayauth/sdk via the core re-export.

Fix: change the inner dep to "*" to match the pattern used by
@relayauth/server and @relayauth/sdk (both of which use "*" for
their sibling workspace deps so publish-time version substitution
follows the actual workspace). Bump core to 0.2.1 so the fix can be
published and picked up.

After merge, republish @relayauth/core@0.2.1 and the nested-sdk
diamond disappears on next npm install.

Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>

Author: kjgbot

packages/core/package.json

@@ -1,6 +1,6 @@
 {
   "name": "@relayauth/core",
-  "version": "0.2.0",
+  "version": "0.2.1",
   "type": "module",
   "main": "dist/index.js",
   "types": "dist/index.d.ts",
@@ -16,7 +16,7 @@
     "typecheck": "tsc --noEmit"
   },
   "dependencies": {
-    "@relayauth/sdk": "^0.1.0",
+    "@relayauth/sdk": "*",
     "yaml": "^2.8.3"
   },
   "peerDependencies": {