feat(wal): implement segment rotation, recovery scanner, and record parser

- wal/segment_manager.go: segment lifecycle with rotation at batch boundaries
- wal/scanner.go: segment discovery, ordering, and continuity validation
- wal/record_parser.go: block-level physical record parsing with tail corruption detection
- Comprehensive tests for all modules, all pass with -race

.omo/boulder.json

@@ -8,7 +8,7 @@
       "plan_name": "phase1-wal",
       "status": "active",
       "started_at": "2026-06-12T05:09:32.588Z",
-      "updated_at": "2026-06-12T05:43:11.052Z",
+      "updated_at": "2026-06-12T05:49:50.501Z",
       "session_ids": [
         "opencode:ses_145c3bae9ffeTB2zbsTym0Cev8"
       ],
@@ -81,6 +81,19 @@
           "status": "completed",
           "ended_at": "2026-06-12T05:43:11.052Z",
           "elapsed_ms": 32768
+        },
+        "todo:11": {
+          "task_key": "todo:11",
+          "task_label": "11",
+          "task_title": "Segment rotation + durable-ready protocol",
+          "session_id": "opencode:ses_145a44184ffeEK5zu36ABE7jHM",
+          "agent": "Sisyphus-Junior",
+          "category": "unspecified-high",
+          "updated_at": "2026-06-12T05:49:50.501Z",
+          "started_at": "2026-06-12T05:48:04.491Z",
+          "status": "completed",
+          "ended_at": "2026-06-12T05:49:50.501Z",
+          "elapsed_ms": 106010
         }
       }
     }
@@ -88,7 +101,7 @@
   "active_plan": "/home/dailz/workspace/src/go-kv/.omo/plans/phase1-wal.md",
   "started_at": "2026-06-12T05:09:32.588Z",
   "status": "active",
-  "updated_at": "2026-06-12T05:43:11.052Z",
+  "updated_at": "2026-06-12T05:49:50.501Z",
   "session_ids": [
     "opencode:ses_145c3bae9ffeTB2zbsTym0Cev8"
   ],
@@ -161,6 +174,19 @@
       "status": "completed",
       "ended_at": "2026-06-12T05:43:11.052Z",
       "elapsed_ms": 32768
+    },
+    "todo:11": {
+      "task_key": "todo:11",
+      "task_label": "11",
+      "task_title": "Segment rotation + durable-ready protocol",
+      "session_id": "opencode:ses_145a44184ffeEK5zu36ABE7jHM",
+      "agent": "Sisyphus-Junior",
+      "category": "unspecified-high",
+      "updated_at": "2026-06-12T05:49:50.501Z",
+      "started_at": "2026-06-12T05:48:04.491Z",
+      "status": "completed",
+      "ended_at": "2026-06-12T05:49:50.501Z",
+      "elapsed_ms": 106010
     }
   },
   "agent": "atlas"

.omo/plans/phase1-wal.md

@@ -891,7 +891,7 @@ Max Concurrent: 6 (Wave 1b)
   **Commit**: YES (with Task 11)
   - Message: `feat(wal): implement segment writer with rotation`
 
-- [ ] 11. Segment rotation + durable-ready protocol
+- [x] 11. Segment rotation + durable-ready protocol
 
   **What to do**:
   - 创建 `wal/segment_manager.go`：管理 segment 的轮转和生命周期
@@ -1180,7 +1180,7 @@ Max Concurrent: 6 (Wave 1b)
   **Commit**: YES
   - Message: `feat(memtable): integrate arena+skiplist with publish/abort`
 
-- [ ] 15. WAL recovery: scanner + record parser
+- [x] 15. WAL recovery: scanner + record parser
 
   **What to do**:
   - 创建 `wal/scanner.go`：`SegmentScanner` — 从 WAL 目录扫描 segment 文件