chore(claude): prune the dead launch.json entry, and the convention that left it (#14979)

`.claude/launch.json` carried a `pr3505-attach-3477` configuration whose
`runtimeArgs` were rooted at `/home/user/objectstack-pr3505/examples/app-showcase`
— a worktree that no longer exists. Delete it.

The entry was not an author's slip: the dogfood skill's section 0 tells every
session to add a named config pointing at its own working directory, and nothing
told anyone to take it back out. So section 0 gains one line beside the existing
add instruction: remove your entry when the worktree goes.


Claude-Session: https://claude.ai/code/session_019RfFHiRCSs3JXLK4cwcfox

Co-authored-by: Claude <noreply@anthropic.com>

Author: claude[bot]

.claude/launch.json

@@ -18,24 +18,6 @@
         "file:/tmp/showcase-dogfood-3777/data.db"
       ],
       "port": 3777
-    },
-    {
-      "name": "pr3505-attach-3477",
-      "runtimeExecutable": "pnpm",
-      "runtimeArgs": [
-        "-C",
-        "/home/user/objectstack-pr3505/examples/app-showcase",
-        "exec",
-        "objectstack",
-        "dev",
-        "--ui",
-        "--seed-admin",
-        "-p",
-        "3477",
-        "-d",
-        "file:/tmp/pr3505-attach/data.db"
-      ],
-      "port": 3477
     }
   ]
 }

.claude/skills/dogfood-verification/SKILL.md

@@ -35,6 +35,7 @@ dev 工作树、dev-server 端口、preview 浏览器全是**共享的**:并行
       `lsof -nP -iTCP:<port> -sTCP:LISTEN`。在 `.claude/launch.json` 加一条指向**本**
       工作目录的具名配置,例如
       `pnpm -C <abs>/examples/app-showcase exec objectstack dev --ui --seed-admin -p <port> -d file:/tmp/<run>/data.db`。
+      工作树没了就**删掉自己那条** —— 死条目让 `preview_start` 挂在缺失的 `pnpm -C` 上。
 - [ ] **同时导出 `OS_PORT` —— 只给 `-p` 不够。** showcase 的自 ping 连接器读的是*环
       境*(`SHOWCASE_SELF_URL`→`OS_PORT`→`PORT`→3000),于是 `fetch failed` 冒充出口被封。
 - [ ] **自有数据**:`--seed-admin` 在空 DB 上给出 `admin@objectos.ai / admin123`。持