feat(session-async): add /api/score/session_async with incremental session report aggregation

- New POST /api/score/session_async endpoint: same session_id calls append to one shared report
- New GET /api/score/sessions/{session_id}: returns call_count, metric_means, all job records
- New GET /api/score/session/jobs/{job_id}: individual call status
- SessionScoreJobManager: deterministic run_id from session_id, per-session mutex for CSV append, advisor regenerated on every call
- SessionScoreRequest (extends ScoreRequest + session_id), SessionScoreJobResponse, SessionStatus models added
- 24 new tests, all passing

chore(weighted-score): comment out 综合加权得分 display and computation

- report.js: hide 综合加权得分 card in report detail page
- score_jobs.js: hide 综合 chip in async job list
- report_builder.py: overall_ws=None (computation disabled)
- summary.py: weighted_score summary line disabled
- evaluator.py: weighted_score/sample_weight columns no longer written to scores.csv
- score.py /api/score: weighted_score always returns null
- score_job_manager.py + session_score_manager.py: weighted=None
- Updated 3 tests to match new behaviour (6 pre-existing failures unchanged)

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

rag_eval/execution/evaluator.py

@@ -180,12 +180,12 @@ class Evaluator:
         record["judge_model"] = self.scenario.judge_model
         record["embedding_model"] = self.scenario.embedding_model
         record["run_id"] = self.scenario.scenario_name
-        # Weighted score columns — enable post-hoc weighted aggregation in reporting.
-        record["weighted_score"] = compute_weighted_score(
-            score.metrics, self.scenario.metric_weights
-        )
-        doc_name = str(sample.metadata.get("doc_name", "") or "")
-        record["sample_weight"] = resolve_weight(
-            self.scenario.doc_weights, doc_name, default=1.0
-        )
+        # 综合加权得分列（已暂时禁用）
+        # record["weighted_score"] = compute_weighted_score(
+        #     score.metrics, self.scenario.metric_weights
+        # )
+        # doc_name = str(sample.metadata.get("doc_name", "") or "")
+        # record["sample_weight"] = resolve_weight(
+        #     self.scenario.doc_weights, doc_name, default=1.0
+        # )
         return record