fix(session): add auto-refresh for expired JWT tokens

- Add isTokenValid() to decode JWT and check exp claim
- Refresh tokens 60 seconds before expiry (buffer)
- Auto-fetch fresh token via SSO-Link when cached token expires
- Clear invalid sessions when refresh fails
- Prevents "exp claim timestamp check failed" errors

JWT tokens from mana-core-auth expire after 15 minutes, but sessions
were cached for 7 days. Now tokens are transparently refreshed when
they expire, keeping users authenticated.

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

services/matrix-stats-bot/src/mydata/mydata.module.ts

@@ -0,0 +1,10 @@
+import { Module } from '@nestjs/common';
+import { ConfigModule } from '@nestjs/config';
+import { MyDataService } from './mydata.service';
+
+@Module({
+	imports: [ConfigModule],
+	providers: [MyDataService],
+	exports: [MyDataService],
+})
+export class MyDataModule {}