feat(p3.2+adr-100): Model Version Tracker + SLO 自治 + KB rot cleaner

Wave 8 P3.2 模型版本追蹤 + ADR-100 SLO 自我治理 + 配套：

P3.2 — Model Version Tracking:
- model_version_probe.py (268 行) — 探測 Ollama / OpenRouter 等 provider 的 model version
- model_version_tracker.py (101 行) — 對齊 PG provider_version_history 表
- migrations/p3_2_provider_version_history.sql + rollback — 25 行 schema
- db/models.py +32 行 — ProviderVersionHistory ORM

ADR-100 — AI 自主化 SLO:
- docs/adr/ADR-100-ai-autonomous-slo.md (167 行) — 飛輪 SLO 設計與閾值
- ops/monitoring/slo-rules.yml (254 行) — Prometheus SLO recording rules + alerts
- ops/monitoring/tests/test_slo_rules.yaml (242 行) — promtool unit tests

整合修改:
- main.py +72 行 — Lifespan 啟動 model_version_probe + KB rot cleaner schedule
- gitea_webhook.py +45 行 — webhook 接收 model 版本變化通知
- ci_auto_repair.py / evidence_snapshot.py / pre_decision_investigator.py — 配合接線

新測試:
- test_kb_rot_cleaner_schedule.py (120 行) — 9 tests pass
- test_slo_rules.yaml — promtool 驗收

Tests: 9 passed (test_kb_rot_cleaner_schedule)

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
Co-Authored-By: Multiple Engineers (P3.2 + ADR-100) <noreply@anthropic.com>

apps/api/src/services/model_version_tracker.py

@@ -0,0 +1,101 @@
+"""
+AI Provider 版本追蹤器 — 每小時探測 5 Provider 並寫入 DB，偵測版本變更
+
+職責：
+  - 排程呼叫 probe_all_providers()
+  - 與 DB 最後一筆比對，判斷 changed 旗標
+  - 寫入 AIProviderVersionHistory
+  - 若有 changed → 記錄 warning log（P3.2.3 alerter 後續整合）
+
+# 2026-04-27 P3.2.2 by Claude
+"""
+from __future__ import annotations
+
+import asyncio
+
+import structlog
+
+logger = structlog.get_logger(__name__)
+
+
+class ModelVersionTracker:
+    """每小時探測所有 AI Provider 版本並寫入 DB"""
+
+    async def run_probe_cycle(self) -> dict:
+        """執行一輪探測：probe → 比對上一筆 → 寫入 DB
+
+        Returns:
+            dict with keys:
+              - probed  : int  — 成功探測的 provider 數
+              - changed : list[str] — 版本有變更的 provider names
+        """
+        from src.db.base import get_db_context
+        from src.db.models import AIProviderVersionHistory
+        from src.services.model_version_probe import probe_all_providers
+        from sqlalchemy import desc, select
+
+        results = await probe_all_providers()
+        changed_providers: list[str] = []
+
+        async with get_db_context() as db:
+            for info in results:
+                # 取最近一筆比對
+                stmt = (
+                    select(AIProviderVersionHistory)
+                    .where(AIProviderVersionHistory.provider == info.provider)
+                    .order_by(desc(AIProviderVersionHistory.captured_at))
+                    .limit(1)
+                )
+                last = (await db.execute(stmt)).scalar_one_or_none()
+
+                changed = (
+                    last is None
+                    or last.version != info.version
+                    or last.digest != info.digest
+                )
+
+                if changed:
+                    changed_providers.append(info.provider)
+
+                db.add(
+                    AIProviderVersionHistory(
+                        provider=info.provider,
+                        model=info.model,
+                        version=info.version,
+                        digest=info.digest,
+                        captured_at=info.captured_at,
+                        prev_version=last.version if last else None,
+                        changed=changed,
+                    )
+                )
+
+            await db.commit()
+
+        if changed_providers:
+            logger.warning(
+                "provider_version_changed",
+                changed=changed_providers,
+                total_probed=len(results),
+            )
+        else:
+            logger.info(
+                "provider_version_stable",
+                total_probed=len(results),
+            )
+
+        return {"probed": len(results), "changed": changed_providers}
+
+
+# =============================================================================
+# Singleton
+# =============================================================================
+
+_tracker: ModelVersionTracker | None = None
+
+
+def get_model_version_tracker() -> ModelVersionTracker:
+    """取得 ModelVersionTracker singleton"""
+    global _tracker
+    if _tracker is None:
+        _tracker = ModelVersionTracker()
+    return _tracker