Home's "N waiting on you" counts exactly the rows /review lists, and asks older than 30 days fold into "N stale, archive?" #5800

Part of #5735. The baseline read "5 waiting on you" over a list of 3, with 4-month-old pulls shown as urgent.

Done when:

• [ ] waitingLine (src/web/studio/kpi_row.ts) counts the same set /review draws, the forge's own needs included. A test compares the two counts on one seeded forge.
• [ ] Asks older than 30 days are left out of the count. The line then adds N stale, archive?, which links to the existing bulk-dismiss preview, so nothing is dismissed without a look.
• [ ] /review folds the same stale asks under one N stale, archive? row.
• [ ] MCP asks gives the same count and the same stale split. A test proves it.

Files: src/web/studio/kpi_row.ts, src/web/studio/review_page.ts, src/flow/kpi_words.ts, src/http/mcp.ts, tests. Risk: #5741 (one button per item) works on the same rows. Keep the row markup it builds on intact.

Parked by the crew: the check stayed red through 2 automatic tries (pull #5824 closed). Planner: split this smaller, or rewrite what done looks like; a person can also say what to try.