feat(complete): Tests, README, Heartbeat, Dashboard

- tests/test_core.py: 6 Unit-Tests (alle grün)
- README.md: Vollständige Dokumentation
- HEARTBEAT.md: Proaktivitäts-Checkliste
- Cron: Backup täglich 2 Uhr

Closes #1, #6

tests/test_core.py

@@ -0,0 +1,106 @@
+#!/usr/bin/env python3
+"""Tests für Second Brain Kern-Module."""
+
+import sys
+import os
+import tempfile
+sys.path.insert(0, os.path.join(os.path.dirname(__file__), "..", "src"))
+
+try:
+    from src.engram import Engram, Grounding, Correctness
+    from src.store import EngramStore
+    from src.retriever import Retriever
+except ImportError:
+    from engram import Engram, Grounding, Correctness
+    from store import EngramStore
+    from retriever import Retriever
+
+
+def test_engram_creation():
+    eg = Engram.create("Test content", source="test", tags=["a", "b"])
+    assert eg.content == "Test content"
+    assert eg.metadata["source"] == "test"
+    assert "a" in eg.metadata["tags"]
+    assert eg.compute_confidence() > 0
+    print("✅ test_engram_creation")
+
+
+def test_correctness():
+    c = Correctness()
+    assert c.score() == 0.5
+    c.confirm("user")
+    assert c.score() == 1.0
+    c.reject("user")
+    assert c.score() == 0.5
+    print("✅ test_correctness")
+
+
+def test_store_crud():
+    with tempfile.NamedTemporaryFile(suffix=".sqlite", delete=False) as f:
+        db_path = f.name
+
+    store = EngramStore(db_path)
+    eg = Engram.create("Store test", tags=["store"])
+    store.save(eg)
+
+    loaded = store.get(str(eg.id))
+    assert loaded is not None
+    assert loaded.content == "Store test"
+    assert store.count() == 1
+
+    store.delete(str(eg.id))
+    assert store.count() == 0
+
+    store.close()
+    os.unlink(db_path)
+    print("✅ test_store_crud")
+
+
+def test_search():
+    with tempfile.NamedTemporaryFile(suffix=".sqlite", delete=False) as f:
+        db_path = f.name
+
+    store = EngramStore(db_path)
+    store.save(Engram.create("Python ist eine Programmiersprache", tags=["coding"]))
+    store.save(Engram.create("SQLite ist eine Datenbank", tags=["db"]))
+    store.save(Engram.create("JavaScript ist eine Sprache", tags=["coding"]))
+
+    ret = Retriever(store)
+    results = ret.retrieve("Programmiersprache Datenbank")
+    assert len(results) >= 2
+
+    results = ret.retrieve("nichtsexistenterbegriff12345")
+    assert len(results) == 0
+
+    store.close()
+    os.unlink(db_path)
+    print("✅ test_search")
+
+
+def test_links():
+    eg1 = Engram.create("Parent")
+    eg2 = Engram.create("Child")
+    eg1.add_link(eg2)
+    assert eg2.id in eg1.links
+    assert eg1.id in eg2.links
+    print("✅ test_links")
+
+
+def test_grounding():
+    eg = Engram.create("Test", grounding=Grounding.VERIFIED)
+    assert eg.metadata["grounding"] == 4
+    conf = eg.compute_confidence()
+    # VERIFIED sollte höheren Confidence geben als UNKNOWN
+    eg2 = Engram.create("Test2", grounding=Grounding.UNKNOWN)
+    assert eg.compute_confidence() > eg2.compute_confidence()
+    print("✅ test_grounding")
+
+
+if __name__ == "__main__":
+    test_engram_creation()
+    test_correctness()
+    test_store_crud()
+    test_search()
+    test_links()
+    test_grounding()
+    print("\n🎉 Alle 6 Tests bestanden!")