feat(systemd): Dashboard-Service, brain_rules, 18 Engramme bewertet, Cron persistent

Neu:
- systemd: secondbrain-dashboard.service (Port 8501, autostart)
- cron_rules.py: Auto-Confirm ab 3x, Archiv nach 30d
- cron_tasks/: heartbeat + backup + brain_rules (persistent)
- openclaw_cron_wrapper.py: subprocess-Isolation (kein SessionTakeover)
- chat_autosave.py: Auto-Save von Chat + Kontext-Anreicherung

Daten:
- 18 unbestätigte Engramme bewertet:
  - 14x CONFIRMED (Fakten/Definitionen korrekt)
  - 3x ARCHIVIERT (historisch, nicht aktuell)
  - 1x CONFIRMED (Regel 73624013)
- 0 offene unbestätigte

Closes Gitea-Issue: #9

chat_autosave.py

@@ -0,0 +1,119 @@
+#!/usr/bin/env python3
+"""
+Chat-Auto-Save: Wertvolle User-Nachrichten → Engramm.
+Wird am Ende jeder Main-Session-Antwort aufgerufen.
+"""
+
+import sys
+import json
+import hashlib
+from pathlib import Path
+
+BRAIN_DIR = Path("/root/.openclaw/workspace/second-brain")
+sys.path.insert(0, str(BRAIN_DIR))
+
+from src.engram import Engram, Grounding
+from src.store import EngramStore
+
+DB_PATH = BRAIN_DIR / "data" / "brain.sqlite"
+
+
+def _hash(text: str) -> str:
+    return hashlib.sha256(text.encode("utf-8")).hexdigest()[:12]
+
+
+def is_fluff(content: str) -> bool:
+    """Prüft ob Inhalt nur Floskel ist."""
+    lower = content.lower().strip().rstrip(".?!")
+    short_fluff = [
+        "hallo", "hi", "hey", "guten tag", "guten morgen", "guten abend",
+        "danke", "ok", "okay", "ja", "nein", "bitte", "gerne", "tschüss",
+        "bis später", "bis morgen", "alles klar", "in ordnung",
+    ]
+    if lower in short_fluff:
+        return True
+    if len(content) < 10 and all(c in " ?,!.;:-" for c in content):
+        return True
+    return False
+
+
+def save_if_worthy(content: str, source: str = "user", tags: list = None,
+                   confidence: float = 0.7, session_id: str = None,
+                   reasoning: str = None) -> dict:
+    """
+    Speichert Nachricht als Engramm wenn sie Wert hat.
+    Wird in jeder Antwort aufgerufen.
+    """
+    
+    if is_fluff(content):
+        return {"saved": False, "reason": "fluff"}
+    
+    store = EngramStore(str(DB_PATH))
+    content_hash = _hash(content)
+    recent = store.get_all(limit=200)
+    for eg in recent:
+        if _hash(eg.content) == content_hash:
+            return {"saved": False, "reason": "duplicate", "id": str(eg.id)}
+    
+    eg = Engram.create(
+        content=content,
+        source=source,
+        tags=tags or ["auto-save", "chat"],
+        session_id=session_id,
+        confidence=confidence,
+        grounding=Grounding.ASSUMPTION,
+    )
+    store.save(eg)
+    
+    return {
+        "saved": True,
+        "id": str(eg.id),
+        "confidence": eg.compute_confidence(),
+        "first8": str(eg.id)[:8],
+    }
+
+
+def enrich_prompt(topic: str, limit: int = 3) -> str:
+    """
+    Holt relevante bestätigte Engramme für Kontext-Anreicherung.
+    Wird VOR jeder Antwort aufgerufen.
+    """
+    store = EngramStore(str(DB_PATH))
+    recent = store.get_all(limit=100)
+    
+    # Einfache Text-Suche (kein FTS wegen Satzzeichen)
+    topic_lower = topic.lower()
+    matches = []
+    for eg in recent:
+        if eg.correctness.confirmed and topic_lower in eg.content.lower():
+            matches.append(eg)
+        elif len(matches) < limit and any(t in topic_lower for t in [t.lower() for t in eg.metadata.get("tags", [])]):
+            matches.append(eg)
+        if len(matches) >= limit:
+            break
+    
+    if not matches:
+        return ""
+    
+    lines = ["\n📚 Relevantes Wissen:"]
+    for eg in matches[:limit]:
+        lines.append(f"  • [{eg.compute_confidence():.0%}] {eg.content[:120]}")
+    
+    return "\n".join(lines)
+
+
+def check_pending(session_id: str = None) -> list:
+    """Gibt unbestätigte Engramme zurück."""
+    store = EngramStore(str(DB_PATH))
+    egs = store.get_all(limit=50)
+    pending = [eg for eg in egs if not eg.correctness.confirmed]
+    return pending
+
+
+if __name__ == "__main__":
+    import sys
+    if len(sys.argv) > 1:
+        result = save_if_worthy(sys.argv[1])
+        print(json.dumps(result, indent=2))
+    else:
+        print("Usage: python3 chat_autosave.py 'Nachricht'")