Every limit the owner can hit is listed on one Limits page with its value and its reason, read from settings, not constants #1476

From #334 (2): every limit is a setting with its reason beside it. #1454 does children. This is the page and the inventory.

Done looks like.

• [ ] src/settings/limits.ts declares each limit the owner can hit (children, crew slots, check concurrency, run budget ceilings, per-account caps): name, default, bounds and a one-sentence reason. The places that use them read from there.
• [ ] /admin/limits (forge admin only) shows each limit's value and reason and changes it. A value out of bounds is refused with its bound named. The POST is same-origin checked, and every change is kept with who made it and when.
• [ ] A test (in GATE) proves that changing a limit changes the behaviour it governs for at least two limits, and that a non-admin gets a 404.
• [ ] grep finds no remaining hard-coded copy of a listed limit. The pull lists the constants it replaced.

Files. src/settings/limits.ts (new), src/web/pages/admin-limits.ts (new), the modules that held the constants, scripts/gate.ts, a new test. Fits: scout.

Parked by the crew: the check failed ("asks that expire, hold and collapse > two green pulls in one repository are one row, and every surface counts it once") and the decider saw no point in another try (pull #1495 closed). Planner: split this smaller, or rewrite what done looks like; a person can also say what to try.