Add KNIEPUNKT Assistant with multi-LLM editorial workflow

Six-step weekly workflow (research → sources → storyline → draft →
quality → publication) supporting Claude, ChatGPT, Gemini, and Mistral
in parallel for creative steps. Web search via Anthropic tool for news
research. Episode index built from 34 existing KNIEPUNKT episodes for
redundancy checks. Sessions persisted as JSON for mid-workflow resume.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

kniepunkt/session.py

@@ -0,0 +1,38 @@
+"""Session state: save and load the weekly editorial workflow state."""
+import json
+from datetime import datetime
+from pathlib import Path
+
+SESSIONS_DIR = Path(__file__).parent.parent / "sessions"
+
+STEPS = ["research", "sources", "storyline", "draft", "quality", "publication", "done"]
+
+
+def new_session() -> dict:
+    return {
+        "date": datetime.today().strftime("%Y-%m-%d"),
+        "step": "research",
+        "research": None,
+        "sources": None,
+        "storyline": None,
+        "draft": None,
+        "quality": None,
+        "publication": None,
+    }
+
+
+def save(session: dict) -> None:
+    SESSIONS_DIR.mkdir(exist_ok=True)
+    path = SESSIONS_DIR / f"{session['date']}.json"
+    with open(path, "w") as f:
+        json.dump(session, f, ensure_ascii=False, indent=2)
+
+
+def load_latest() -> dict | None:
+    if not SESSIONS_DIR.exists():
+        return None
+    files = sorted(SESSIONS_DIR.glob("*.json"), reverse=True)
+    if not files:
+        return None
+    with open(files[0]) as f:
+        return json.load(f)