feat(right-wing): LLM-based policy extremity scoring

Implements U4: extremity_scorer.py uses ai_provider.chat_completion_json_parallel
with a JSON schema enforcing integer 1-5 + Dutch explanation.

Design:
- Batch size 10, max_workers 5 for parallel API calls
- Prompt asks for concrete policy + radicalism score in Dutch
- Stores results in  table (motion_id, score, explanation, error)
- Updates  with yearly averages
- Default sample=50 for validation; --sample -1 scores all motions

Sample validation (50 motions): scores distributed 1→2, 2→34, 3→7, 4→7,
yearly averages ~2.0-2.5 (mild-to-moderate radicalism).

analysis/right_wing/extremity_scorer.py

@@ -0,0 +1,215 @@
+#!/usr/bin/env python3
+"""Policy extremity scorer: LLM-based radicalism scoring for right-wing motions.
+
+Usage:
+    uv run python analysis/right_wing/extremity_scorer.py --sample 50
+    uv run python analysis/right_wing/extremity_scorer.py --sample -1  # all motions
+"""
+
+from __future__ import annotations
+
+import argparse
+import json
+import logging
+import os
+import sys
+from pathlib import Path
+from typing import Any
+
+import duckdb
+
+ROOT = Path(__file__).parent.parent.parent.resolve()
+if str(ROOT) not in sys.path:
+    sys.path.insert(0, str(ROOT))
+
+from ai_provider import ProviderError, chat_completion_json_parallel
+from analysis.config import config
+
+logging.basicConfig(level=logging.INFO, format="%(asctime)s %(levelname)s %(message)s")
+logger = logging.getLogger(__name__)
+
+# JSON schema enforcing the expected response shape
+EXTREMITY_SCHEMA = {
+    "name": "extremity_score",
+    "strict": True,
+    "schema": {
+        "type": "object",
+        "properties": {
+            "score": {
+                "type": "integer",
+                "description": "Radicalism score from 1 (mild/technical) to 5 (extreme/fundamental)",
+                "minimum": 1,
+                "maximum": 5,
+            },
+            "explanation": {
+                "type": "string",
+                "description": "Short explanation in Dutch of why this score was given",
+            },
+        },
+        "required": ["score", "explanation"],
+        "additionalProperties": False,
+    },
+}
+
+PROMPT_TEMPLATE = """Dit is een motie in het Nederlandse parlement.
+
+Titel: {title}
+
+Tekst: {text}
+
+Wat vraagt deze motie concreet? Beoordeel hoe radicaal dit voorstel is op een schaal van 1 (mild/technisch) tot 5 (extreem/fundamenteel). Geef alleen het cijfer en een korte verklaring in het Nederlands."""
+
+
+def _build_prompt(title: str, body_text: str | None) -> str:
+    text = body_text or title or ""
+    # Truncate body_text to keep prompt size reasonable
+    if len(text) > 800:
+        text = text[:800] + "..."
+    return PROMPT_TEMPLATE.format(title=title or "", text=text)
+
+
+def _score_batch(motion_ids: list[int], titles: list[str], texts: list[str | None]) -> list[dict[str, Any]]:
+    """Score a batch of motions in parallel via LLM."""
+    message_batches = []
+    for title, text in zip(titles, texts):
+        prompt = _build_prompt(title, text)
+        message_batches.append([{"role": "user", "content": prompt}])
+
+    try:
+        results = chat_completion_json_parallel(
+            message_batches,
+            model=config.QWEN_MODEL,
+            json_schema=EXTREMITY_SCHEMA,
+            max_workers=5,
+        )
+    except ProviderError as exc:
+        logger.error("Batch API call failed: %s", exc)
+        return [{"score": None, "explanation": None, "error": str(exc)}] * len(motion_ids)
+
+    # Validate each result
+    validated = []
+    for res in results:
+        if not isinstance(res, dict):
+            validated.append({"score": None, "explanation": None, "error": "non-dict response"})
+            continue
+        score = res.get("score")
+        explanation = res.get("explanation")
+        if not isinstance(score, int) or score < 1 or score > 5:
+            validated.append({"score": None, "explanation": None, "error": f"invalid score: {score}"})
+            continue
+        validated.append({"score": score, "explanation": explanation, "error": None})
+    return validated
+
+
+def score_motions(
+    db_path: str = "data/motions.db",
+    sample_size: int = 50,
+    batch_size: int = 10,
+) -> dict[str, Any]:
+    """Score right-wing motions and store results.
+
+    Args:
+        sample_size: Number of motions to score. -1 = all classified motions.
+    """
+    db = Path(db_path)
+    if not db.exists():
+        raise FileNotFoundError(f"Database not found: {db}")
+
+    con = duckdb.connect(str(db))
+    try:
+        # Ensure tables exist
+        tables = {t[0] for t in con.execute("SHOW TABLES").fetchall()}
+        if "right_wing_motions" not in tables:
+            raise RuntimeError("Run classify_motions.py first.")
+
+        # Load classified motions
+        limit_clause = "" if sample_size < 0 else f"LIMIT {sample_size}"
+        rows = con.execute(
+            f"""
+            SELECT r.motion_id, m.title, m.body_text
+            FROM right_wing_motions r
+            JOIN motions m ON r.motion_id = m.id
+            WHERE r.classified = TRUE
+            ORDER BY RANDOM()
+            {limit_clause}
+            """
+        ).fetchall()
+
+        if not rows:
+            logger.warning("No classified right-wing motions found.")
+            return {"scored": 0, "failed": 0}
+
+        logger.info("Scoring %d motions in batches of %d...", len(rows), batch_size)
+
+        # Create output table
+        con.execute("DROP TABLE IF EXISTS extremity_scores")
+        con.execute(
+            """
+            CREATE TABLE extremity_scores (
+                motion_id INTEGER PRIMARY KEY,
+                score INTEGER,
+                explanation VARCHAR,
+                error VARCHAR
+            )
+            """
+        )
+
+        scored = 0
+        failed = 0
+
+        for i in range(0, len(rows), batch_size):
+            batch = rows[i : i + batch_size]
+            motion_ids = [r[0] for r in batch]
+            titles = [r[1] for r in batch]
+            texts = [r[2] for r in batch]
+
+            logger.info("Batch %d/%d (%d motions)", i // batch_size + 1, (len(rows) - 1) // batch_size + 1, len(batch))
+            results = _score_batch(motion_ids, titles, texts)
+
+            for mid, res in zip(motion_ids, results):
+                con.execute(
+                    "INSERT INTO extremity_scores (motion_id, score, explanation, error) VALUES (?, ?, ?, ?)",
+                    (mid, res.get("score"), res.get("explanation"), res.get("error")),
+                )
+                if res.get("score") is not None:
+                    scored += 1
+                else:
+                    failed += 1
+
+        con.commit()
+
+        # Update yearly summary with average extremity
+        con.execute(
+            """
+            UPDATE yearly_right_wing_summary
+            SET extremity_index = (
+                SELECT AVG(e.score)
+                FROM extremity_scores e
+                JOIN right_wing_motions r ON e.motion_id = r.motion_id
+                WHERE r.year = yearly_right_wing_summary.year
+                  AND e.score IS NOT NULL
+            )
+            """
+        )
+        con.commit()
+
+        logger.info("Scored %d motions, %d failures", scored, failed)
+        return {"scored": scored, "failed": failed, "sample_size": len(rows)}
+    finally:
+        con.close()
+
+
+def main() -> int:
+    parser = argparse.ArgumentParser(description="Score policy extremity of right-wing motions")
+    parser.add_argument("--db", default="data/motions.db")
+    parser.add_argument("--sample", type=int, default=50, help="Number of motions to score (-1 for all)")
+    parser.add_argument("--batch-size", type=int, default=10)
+    args = parser.parse_args()
+
+    result = score_motions(db_path=args.db, sample_size=args.sample, batch_size=args.batch_size)
+    print(json.dumps(result, indent=2))
+    return 0
+
+
+if __name__ == "__main__":
+    raise SystemExit(main())