feat: initial commit of astra local voice agent

Lokaler deutscher Sprachagent für Apple Silicon: Pipecat-Pipeline mit
Nemotron-ASR (MLX), Qwen über natives Ollama /api/chat, und Pocket TTS.
Loopback-only WebRTC-Server mit Origin/Host-Härtung.

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01LVgSHNHdRx3UNTBodFmhRA

tests/test_core.py

@@ -0,0 +1,51 @@
+import unittest
+
+from astra.core import Settings, build_request, local_origin_allowed, trim_messages
+
+
+class CoreTests(unittest.TestCase):
+    def test_thinking_is_disabled_in_every_native_request(self):
+        request = build_request(Settings(), [{"role": "user", "content": "Hallo"}])
+        self.assertIs(request["think"], False)
+        self.assertIs(request["stream"], True)
+        self.assertEqual(request["model"], "qwen3.5:latest")
+        self.assertNotIn("think", request["options"])
+        self.assertEqual(request["options"]["num_ctx"], 4096)
+
+    def test_history_stays_bounded_and_preserves_system_and_latest_user(self):
+        messages = [{"role": "system", "content": "Deutsch"}]
+        for i in range(40):
+            messages.extend(
+                [
+                    {"role": "user", "content": f"Frage {i}"},
+                    {"role": "assistant", "content": "Antwort " * 100},
+                ]
+            )
+        messages.append({"role": "user", "content": "Neueste Frage"})
+        trimmed = trim_messages(messages, max_chars=5000)
+        self.assertEqual(trimmed[0], messages[0])
+        self.assertEqual(trimmed[1]["role"], "user")
+        self.assertEqual(trimmed[-1], messages[-1])
+        self.assertLessEqual(sum(len(m["content"]) for m in trimmed), 5000)
+        self.assertEqual(len(messages), 82)
+
+    def test_rejects_foreign_web_origins(self):
+        self.assertTrue(local_origin_allowed("http://localhost:7860"))
+        self.assertTrue(local_origin_allowed("http://127.0.0.1:7860"))
+        self.assertFalse(local_origin_allowed("https://evil.example"))
+        self.assertFalse(local_origin_allowed("http://localhost.evil.example:7860"))
+        self.assertFalse(local_origin_allowed("null"))
+
+    def test_huge_last_message_is_bounded(self):
+        trimmed = trim_messages(
+            [
+                {"role": "system", "content": "Deutsch"},
+                {"role": "user", "content": "x" * 20000},
+            ],
+            max_chars=5000,
+        )
+        self.assertLessEqual(sum(len(m["content"]) for m in trimmed), 5000)
+
+
+if __name__ == "__main__":
+    unittest.main()