feat(core): Engram, Store, Retriever, CLI - Grundsystem Second Brain

- src/engram.py: Gedaechtniseinheit mit Confidence, Correctness, Links
- src/store.py: SQLite FTS5 persistenter Speicher
- src/retriever.py: Hybrid Suche + Reranking
- src/cli.py: Kommandozeilen-Interface

Issue: #1

src/cli.py

@@ -0,0 +1,172 @@
+#!/usr/bin/env python3
+"""
+Second Brain CLI - direkte Nutzung ohne externe Abhängigkeiten.
+
+Usage:
+    python -m src.cli add "Das ist ein Faktum" --tag wichtig --source user
+    python -m src.cli search "Faktum"
+    python -m src.cli show <id>
+    python -m src.cli confirm <id>
+    python -m src.cli reject <id>
+    python -m src.cli list
+    python -m src.cli stats
+    python -m src.cli export backup.jsonl
+"""
+
+import sys
+import json
+import argparse
+from pathlib import Path
+
+from .store import EngramStore
+from .engram import Engram, Grounding
+from .retriever import Retriever
+
+DB_PATH = Path(__file__).parent.parent / "data" / "brain.sqlite"
+
+
+def get_store():
+    DB_PATH.parent.mkdir(parents=True, exist_ok=True)
+    return EngramStore(str(DB_PATH))
+
+
+def cmd_add(args):
+    store = get_store()
+    eg = Engram.create(
+        content=" ".join(args.content),
+        source=args.source,
+        tags=args.tag,
+        grounding=Grounding[args.grounding] if args.grounding else Grounding.ASSUMPTION,
+    )
+    store.save(eg)
+    print(f"Created: {eg.id}\n  Content: {eg.content[:100]}\n  Confidence: {eg.compute_confidence():.2f}")
+
+
+def cmd_search(args):
+    store = get_store()
+    ret = Retriever(store)
+    results = ret.retrieve(
+        " ".join(args.query),
+        limit=args.limit,
+        min_confidence=args.min_confidence,
+        tag_filter=args.tag,
+    )
+    print(f"\n=== {len(results)} Results ===")
+    for r in results:
+        eg = r["engram"]
+        conf = eg.compute_confidence()
+        marker = "✅" if conf > 0.7 else "⚠️" if conf > 0.4 else "❌"
+        print(f"\n{marker} [{str(eg.id)[:8]}] Score: {conf:.2f} ({r['match_type']})")
+        print(f"   {eg.content[:120]}{'...' if len(eg.content) > 120 else ''}")
+        print(f"   Tags: {', '.join(eg.metadata.get('tags', []))} | Source: {eg.metadata.get('source')}")
+        print(f"   Access: {eg.metadata.get('access_count', 0)} | Reviews: +{eg.correctness.confirmations}/-{eg.correctness.rejections}")
+
+
+def cmd_show(args):
+    store = get_store()
+    eg = store.get(args.id)
+    if not eg:
+        print(f"Not found: {args.id}")
+        return
+    print(json.dumps(eg.to_dict(), indent=2, ensure_ascii=False, default=str))
+
+
+def cmd_confirm(args):
+    store = get_store()
+    eg = store.get(args.id)
+    if not eg:
+        print(f"Not found: {args.id}")
+        return
+    eg.correctness.confirm(by="user", note=args.note or "Confirmed via CLI")
+    store.save(eg)
+    print(f"✅ Confirmed [{str(eg.id)[:8]}] -> Confidence: {eg.compute_confidence():.2f}")
+
+
+def cmd_reject(args):
+    store = get_store()
+    eg = store.get(args.id)
+    if not eg:
+        print(f"Not found: {args.id}")
+        return
+    eg.correctness.reject(by="user", note=args.note or "Rejected via CLI")
+    store.save(eg)
+    print(f"❌ Rejected [{str(eg.id)[:8]}] -> Confidence: {eg.compute_confidence():.2f}")
+
+
+def cmd_list(args):
+    store = get_store()
+    egs = store.get_all(limit=args.limit)
+    print(f"\n=== {len(egs)} Engrams ===")
+    for eg in egs:
+        conf = eg.compute_confidence()
+        marker = "✅" if conf > 0.7 else "⚠️" if conf > 0.4 else "❌"
+        print(f"{marker} [{str(eg.id)[:8]}] ({conf:.2f}) {eg.content[:60]}{'...' if len(eg.content) > 60 else ''}")
+
+
+def cmd_stats(args):
+    store = get_store()
+    ret = Retriever(store)
+    s = ret.stats()
+    print("\n=== Second Brain Stats ===")
+    print(f"  Total Engrams: {s['total_engrams']}")
+    print(f"  Confirmed: {s['confirmed']}")
+    print(f"  Unconfirmed: {s['unconfirmed']}")
+    print(f"  Sources:")
+    for src, count in s.get("sources", {}).items():
+        print(f"    {src}: {count}")
+    print(f"  DB Size: {s['db_size_bytes'] / 1024:.1f} KB")
+
+
+def cmd_export(args):
+    store = get_store()
+    count = store.export_jsonl(args.path)
+    print(f"Exported {count} engrams to {args.path}")
+
+
+def main():
+    parser = argparse.ArgumentParser(description="Second Brain CLI")
+    sub = parser.add_subparsers(dest="cmd")
+
+    p_add = sub.add_parser("add", help="Add a new engram")
+    p_add.add_argument("content", nargs="+")
+    p_add.add_argument("--tag", action="append", default=[])
+    p_add.add_argument("--source", default="user")
+    p_add.add_argument("--grounding", choices=[g.name for g in Grounding])
+
+    p_search = sub.add_parser("search", help="Search engrams")
+    p_search.add_argument("query", nargs="+")
+    p_search.add_argument("--limit", type=int, default=5)
+    p_search.add_argument("--min-confidence", type=float, default=0.0)
+    p_search.add_argument("--tag", default=None)
+
+    p_show = sub.add_parser("show", help="Show engram details")
+    p_show.add_argument("id")
+
+    p_confirm = sub.add_parser("confirm", help="Confirm an engram")
+    p_confirm.add_argument("id")
+    p_confirm.add_argument("--note", default="")
+
+    p_reject = sub.add_parser("reject", help="Reject an engram")
+    p_reject.add_argument("id")
+    p_reject.add_argument("--note", default="")
+
+    p_list = sub.add_parser("list", help="List recent engrams")
+    p_list.add_argument("--limit", type=int, default=20)
+
+    p_stats = sub.add_parser("stats", help="Show statistics")
+
+    p_export = sub.add_parser("export", help="Export to JSONL")
+    p_export.add_argument("path")
+
+    args = parser.parse_args()
+    if not args.cmd:
+        parser.print_help()
+        return
+
+    {"add": cmd_add, "search": cmd_search, "show": cmd_show,
+     "confirm": cmd_confirm, "reject": cmd_reject, "list": cmd_list,
+     "stats": cmd_stats, "export": cmd_export}[args.cmd](args)
+
+
+if __name__ == "__main__":
+    main()