docs(test_framework): add comprehensive integration test guide and fix runner blocking issue

- Document exception handling, zero-value BotResult trap, shared adversary bots
- Add offline parsing example using parseServerOutput
- Skip tests gracefully when JARs missing (guard before suite blocks)
- Fix blocking readLine in runner_process.nim: poll with 50ms sleep + atEnd check
  (was preventing timeout enforcement, now blocks correctly during battle)
- Add test task to QBot.nimble and config.nims setup docs to AGENTS.md
- Add debug logging to TestBattleRunner for bot identity tracking

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

QBot_garage/QBot.nimble

@@ -10,3 +10,6 @@ bin           = @["QBot"]
 requires "nim >= 2.0.0"
 # tankroyale_botapi and radar_lock are vendored in-tree (common_libs/) and wired via
 # config.nims --path; no nimble dependency so builds never touch ~/.nimble/pkgs2.
+
+task test, "Run integration tests":
+  exec "nim c -r --path:../common_libs tests/test_basic_battle.nim"