feat(e2e): #146 MTProto Telegram user client runner

- Add standalone C# console runner tests/e2e/runner/ using WTelegramClient
- Provide TelegramUserClient wrapper: login, create supergroup, invite bot,
  send messages/commands, read recent messages, wait for bot reply
- Add .env.example and runner .gitignore to keep secrets/session files out of git
- Update E2E README with runner instructions and status table
- Runner project intentionally excluded from GM-Relay.slnx to avoid CI/AOT impact

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

tests/e2e/.gitignore

@@ -1,18 +1,31 @@
-# Python cache and virtual environments
+# Python
 __pycache__/
-*.pyc
-*.pyo
-*.pyd
-.env
+*.py[cod]
+*$py.class
 .venv/
+env/
 venv/
 
-# Playwright artifacts
-screenshots/
-test-results/
-playwright-report/
+# Secrets
+.env
+*.env
 
-# E2E runtime state
+# Telegram sessions
 *.session
 *.session-journal
-session-*.json
+
+# Playwright artifacts
+test-results/
+playwright-report/
+playwright/.cache/
+
+# .NET build artifacts
+bin/
+obj/
+packages.lock.json
+
+# IDE
+.vscode/
+.idea/
+*.user
+*.suo