feat(phase25): Nemotron 主動防禦三方向 P0+P1+P2 完整實作

P0 - DIAGNOSE Privacy-First Routing:
- ai_router.py: _local_fallback_chain [NEMOTRON→OLLAMA→REJECT]
- DIAGNOSE 意圖 override 改為 NEMOTRON (原 OLLAMA)
- DIAGNOSE fallback 使用 local-only 鏈，不觸碰雲端
- 全部失敗時 REJECT + Telegram 通知
- config.py: NEMOTRON_DIAGNOSE_TIMEOUT_SECONDS=30, OLLAMA_DIAGNOSE_TIMEOUT_SECONDS=60
- nemotron.py: 根據 context[task_type] 選擇 timeout

P1 - Knowledge Auto-Harvesting:
- models/knowledge.py: EntryType.AUTO_RUNBOOK + ANTI_PATTERN + symptoms_hash
- EntryStatus.PUBLISHED (ANTI_PATTERN 直接發布，無需審核)
- models/playbook.py: SymptomPattern.compute_hash() (16字元確定性 hash)
- services/runbook_generator.py: NemotronRunbookGenerator (v1.1)
  - generate_runbook() → AUTO_RUNBOOK (DRAFT) + Telegram 審核 card
  - generate_anti_pattern() → ANTI_PATTERN (PUBLISHED) + Telegram 通知
  - 使用 nvidia.chat() (正確介面)，Nemotron 超時時 Minimal fallback
- knowledge_service.py: check_anti_pattern(symptoms_hash, days=7)
- db/models.py: symptoms_hash VARCHAR(16) + ix_knowledge_symptoms_hash
- repositories/knowledge_repository.py: create() 支援 symptoms_hash + status
- auto_repair_service.py: anti_pattern_gate 在 decide() + runbook hook 在 execute()
- migrations/phase8_symptoms_hash.sql: ALTER TABLE + partial index + PUBLISHED constraint

P2 - Config Drift Detection:
- models/drift.py: DriftItem/DriftReport/DriftLevel/DriftIntent/DriftStatus
- services/drift_detector.py: GitStateReader + K8sStateReader + DriftDetector
- services/drift_analyzer.py: 白名單過濾 + DriftLevel 分級
- services/drift_interpreter.py: NemotronDriftInterpreter（意圖分析，不生成修復指令）
- services/drift_remediator.py: rollback(kubectl apply) + adopt(git push gitea)
- api/v1/drift.py: POST /scan, GET /reports, POST /rollback, POST /adopt
- migrations/phase9_drift_reports.sql: drift_reports 表
- k8s/drift-cronjob.yaml: 每小時自動掃描 CronJob

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

apps/api/src/main.py

@@ -57,6 +57,7 @@ from src.api.v1 import (
 from src.api.v1 import (
     signoz_webhook as signoz_webhook_v1,  # Phase 21: SignOz → Telegram (ADR-037)
 )
+from src.api.v1 import drift as drift_v1  # Phase 25 P2: Config Drift Detection
 from src.api.v1 import monitoring as monitoring_v1  # 2026-04-03: 監控工具狀態
 from src.api.v1 import stats as stats_v1  # Phase 6.5: Statistics Analytics
 from src.api.v1 import telegram as telegram_v1  # Phase 5.4: Telegram Gateway
@@ -422,6 +423,9 @@ app.include_router(
 app.include_router(
     auto_repair_v1.router, prefix="/api/v1", tags=["Auto Repair"]
 )  # #8: 自動升級決策
+app.include_router(
+    drift_v1.router, prefix="/api/v1", tags=["Drift Detection"]
+)  # Phase 25 P2: Config Drift Detection
 app.include_router(
     errors_v1.router, prefix="/api/v1", tags=["Errors"]
 )  # #40: Sentry 錯誤 BFF API