Initial import of Shirobana bot backend

Include utility modules, shared channels, prompts, read-only skills, wardrobe memory and regression tests. Externalize legacy credentials and exclude private runtime state.

tests/test_akaros_persona.py

@@ -0,0 +1,22 @@
+"""Akaros mailbox is a personal asset available without keyword activation."""
+
+from pathlib import Path
+import sys
+import unittest
+
+BASE = Path(__file__).resolve().parents[1]
+sys.path[:0] = [str(BASE / "bot-utility"), str(BASE)]
+
+from chat import engine
+
+
+class AkarosPersonaTests(unittest.TestCase):
+    def test_mailbox_is_personal_asset_with_autonomous_tool_selection(self):
+        self.assertIn("shirobana@akaros.si", engine.BASE_PROMPT)
+        self.assertIn("个人资产", engine.BASE_PROMPT)
+        self.assertIn("不要求用户特别指定服务名", engine.BASE_PROMPT)
+        self.assertIn("不得在没有明确任务或合理上下文时", engine.BASE_PROMPT)
+
+
+if __name__ == "__main__":
+    unittest.main()