docs: mark PEND reason end-to-end done (bug-1513), note main_reason follow-up

- aibot_poc_investiagting.md: PEND reason 调查完成 + 转换层补全；新增遗留项（main_reason 恒 0）
- buglog.json: bug-1513 entry
- memory.md: session log

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

.wolf/buglog.json

@@ -15018,5 +15018,24 @@
     ],
     "occurrences": 1,
     "last_seen": "2026-08-13"
+  },
+  {
+    "id": "bug-1513",
+    "timestamp": "2026-08-13",
+    "error_message": "PEND reason 字段 pending_reason 声明了但恒为空：scheduler 已计算并 setpreason 到 controller，controller 已存 job->pend_reasons，但 API/SSE 查询作业永远拿不到（MCP 无法解释'为什么作业在等'）",
+    "file": "src/controller/apiserver.c + src/frontend/apiserver/backend/{convert,convert_pure}.go + models/jobs.go",
+    "root_cause": "两个缺口叠加：(1) controller 的 apiserver_job_hook_fun 不处理 HOOK_DETAIL_SETPREASON——setpreason 事件不触发任何 JOB_* 推送，apiserver 永远收不到 pend_reasons 变化的作业（JOB_NEW/UPDATE/START/EXIT 才推）；(2) apiserver 转换层 cJobToModel/rawJobToModel 从不读 C 的 xce_job_t.pend_reasons，且 JOB_DEFAULT_COLUMN 不含 pending_reason（默认查询不选该字段）。",
+    "fix": "(1) apiserver_job_hook_fun 加 case HOOK_DETAIL_SETPREASON 复用 apiserver_job_update_fun 推 updateJob；(2) cJobToModel/rawJobToModel 提取 pend_reasons（main_reason + host/res reasons）marshal 为 JSONB 塞进 models.JobInfo.PendingReason；JOB_DEFAULT_COLUMN 加 pending_reason。集群验证：resreq type==nosuchhost 作业 PEND 返回 host_reasons [{t1,3},{t2,3},{t3,3}]（3=MATCH_FAIL）。commit ac6131d。遗留：main_reason 恒 0（allocator 只加明细 reason），修法待定。",
+    "tags": [
+      "apiserver",
+      "pend-reason",
+      "setpreason-hook",
+      "conversion-gap",
+      "scheduler-agent",
+      "fixed"
+    ],
+    "related_bugs": [],
+    "occurrences": 1,
+    "last_seen": "2026-08-13"
   }
 ]