[enhancement] Per-run knobs configurable too — per-tree budget ($5/50/depth-4) and Loop max-iterations, via the same UI + MCP surfaces

[serge-ivo]

Part of the budget-configurability epic — the “all of them” completeness item.

Scope

Beyond the account circuit breaker, make the run-level bounds settable through the same config resolver, UI, and MCP:

• Per-delegation-tree budget (DEFAULT_LIMITS in workers/api/src/lib/delegation-budget.ts): costMicros ($5), delegations (50), maxDepth (4). Today only the cost ceiling is auto-derived (p95 × headroom in openBudget); make the defaults explicit and overridable.
• Loop max-iterations (the “iter 12/50” cap the Loop orchestrator enforces): expose as a per-instance / per-run setting rather than a fixed 50.

Clamp each to a safe maximum. Reuse the resolver + endpoints from the backend/MCP tickets; no separate plumbing.

[serge-ivo]

Part of epic #478.

[serge-ivo]

Parked under #485 — AI budget enforcement is demoted to observe-only (BUDGET_ENFORCE default off) until paid launch, so there is nothing to configure/edit yet. Resume when enforcement returns.

When #475 is resumed specifically: ship the limits UI disabled with a visible "enforcement off" note (mirrors the note now on the console Usage page).