ADR-006 v2.0: Sidecar V2 architecture revision based on review feedback

Incorporated feedback from 4 reviewers:
- 徐聪: AES key management, emergency channel, concurrency control, DDL indexes
- 陆怀瑾: P0 phase, schedule buffer, deployment topology, V1 compat checklist
- 严维序: SQLite backup, monitoring, cooldown persistence, port plan, rollback
- 沈路明: queue design, health check, per-model RPM decision, key validation, dashboard panels

Key additions:
+ Queue flow control design (FIFO + priority, capacity 500, REJECT overflow)
+ Provider health check (active probe + passive stats hybrid)
+ Per-model RPM decision (Provider-level V2, Model-level V3)
+ Key validation on add (test call with error feedback)
+ AES key management (SIDECAR_ENCRYPTION_KEY env var, backup SOP)
+ Emergency channel (10% RPM during full cooldown)
+ SQLite backup strategy (cron .backup, 7-day retention)
+ SQLite monitoring Prometheus metrics (db_size, wal_size, integrity)
+ Full DDL with indexes (ON CONFLICT, BEGIN IMMEDIATE patterns)
+ Dashboard panel list (5 panels: status, trends, history)
+ V1 compatibility checklist (13 items)
+ V1->V2 migration SOP with rollback plan
+ Deployment topology (systemd + Docker, port plan, firewall)
+ Log aggregation policy (logrotate: 10MB/30days)
+ Schedule revised: 71h/12days (added P0 + buffer)

Co-authored-by: multica-agent <github@multica.ai>

docs/architecture/sidecar-v2-topology.mmd

@@ -0,0 +1,58 @@
+flowchart TB
+    subgraph OC["OpenClaw Gateway"]
+        OC_SCHED["OpenClaw 调度器"]
+        OC_FB["OpenClaw Fallback<br/>传统配置链路"]
+    end
+
+    subgraph SIDECAR["Sidecar V2 systemd/Docker"]
+        direction TB
+
+        subgraph ENTRY["入口层"]
+            GW["API Gateway :9190<br/>FastAPI + 路由匹配"]
+        end
+
+        subgraph CORE["核心调度层"]
+            LB["负载均衡器<br/>Weighted RR 5-10s刷新"]
+            QM["队列管理器<br/>FIFO + 优先级<br/>容量500 + 溢出策略"]
+        end
+
+        subgraph POOLS["Provider 池层"]
+            MP["主池 Main Pool"]
+            FP["Fallback 池"]
+            CP["冷却池<br/>Cooldown Pool"]
+        end
+
+        subgraph FLOW["流控层"]
+            RL["Rate Limiter<br/>Per-Provider Token Bucket"]
+            CD["Cooldown Detector<br/>429检测+指数退避<br/>+紧急通道10%RPM"]
+        end
+
+        subgraph STATS["存储与统计层"]
+            MT["Metrics :9191<br/>Prometheus"]
+            ST["统计引擎<br/>Token/费用/调用量"]
+            DB[("SQLite WAL<br/>sidecar_v2.db<br/>+ cron备份")]
+        end
+
+        subgraph WEBUI["WebUI 层 :9190"]
+            UI["Dashboard<br/>SSE 实时推送"]
+            AP["Admin API<br/>Provider CRUD<br/>Bearer Token 鉴权"]
+        end
+    end
+
+    OC_SCHED --> GW
+    GW --> LB
+    LB --> QM
+    QM --> RL
+    RL --> MP
+    RL --> FP
+    MP -.->|"429 触发冷却"| CP
+    MP -->|"全部冷却"| FP
+    FP -->|"全部冷却"| OC_FB
+    CP -.->|"冷却结束恢复"| MP
+    RL --> CD
+    CD -.->|"紧急通道 10% RPM"| MP
+    LB --> MT
+    MT --> ST
+    ST --> DB
+    DB --> UI
+    AP --> DB