Update nexus wiki content

wiki/concepts/ZeroDataLossGuarantee.md

@@ -0,0 +1,43 @@
+---
+title: "Zero Data Loss Guarantee"
+type: concept
+tags: []
+last_updated: 2026-05-01
+---
+
+## Definition
+
+通过数学约束强制执行 `Source_Rows == Success_Rows + Quarantine_Rows` 的数据修复保证机制。任何不匹配立即触发 Sev-1 告警与系统异常。
+
+## Invariant
+
+```
+Source_Rows == Success_Rows + Quarantine_Rows
+```
+
+## Row Lifecycle
+
+| State | Description | Destination |
+|-------|-------------|-------------|
+| `AI_FIXED` | SLM 置信度 ≥ 0.75，lambda 验证通过 | Staging → Production |
+| `HUMAN_REVIEW` | 置信度 < 0.75，或无法自动修复 | Human Quarantine Dashboard |
+
+## Guarantees
+
+- **Mathematical constraint, not a goal**: 不满足等式时系统立即失败，不允许静默通过
+- **Full tracking**: 每条异常行在修复生命周期中始终被追踪
+- **No silent corruption**: 修复后的数据先到 staging，确认后才写生产
+
+## Alert Conditions
+
+```python
+if source != success + quarantine:
+    trigger_alert(severity="SEV1", message=f"DATA LOSS DETECTED: {missing} rows")
+    raise DataLossException(...)
+```
+
+## Related
+
+- [[Semantic Anomaly Compression]]
+- [[Air-Gapped SLM Fix Generation]]
+- [[Lambda Safety Gate]]