Fix getLogger() singleton bug causing all loggers to share the same context

The getLogger() function was using a single defaultLogger variable that
would only be initialized once with the first context. All subsequent
calls with different contexts would return the same logger instance,
causing all logs to show the same context prefix.

Changed to use a Map-based cache that stores separate logger instances
per context, ensuring each context gets its own logger with the correct
context name.

Bump version to 1.0.1-beta.3

🤖 Generated with [Claude Code](https://claude.com/claude-code)

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

package.json

@@ -1,10 +1,10 @@
 {
   "name": "@metatrom/logger",
-  "version": "1.0.1-beta.2",
+  "version": "1.0.1-beta.3",
   "main": "index.ts",
   "type": "module",
   "metatrom": {
-    "ior": "com.metatrom.universal-components.logger@1.0.1-beta.2",
+    "ior": "com.metatrom.universal-components.logger@1.0.1-beta.3",
     "capabilities": {
       "p2p": false,
       "contracts": false,