[frontend] Budget & limits settings surface — show 24h consumption vs each ceiling + distance-to-limit, and edit the limits (console owner + admin)

[serge-ivo]

Depends on the config resolver (backend ticket).

Problem

The account circuit breaker (250M tokens / $50 charged per 24h) is invisible until it fires — the number only appears in the refusal message after work is already blocked. The console Usage page shows consumption from the ai_usage ledger but never the ceiling or how close you are. There is no field anywhere to change the limit.

Scope

1. Usage/Budget panel (console, account owner): for each ceiling show current rolling-24h consumption, the ceiling, and distance-to-limit (a gauge), plus per-tree defaults and Loop iteration cap. Editable where policy allows (clamped to the max from the backend).
2. Admin portal: platform-default ceilings + per-account overrides (the operator view), living beside the existing /admin/settings surface.
3. Wire both to the new get/set endpoints from the backend + MCP tickets. No new source of truth in the client.

Notes

Folds in the earlier “breaker is invisible” gap. Admin portal is at /admin (host worker), role-gated; see #108 re: the Cloudflare Access perimeter.

[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).

[serge-ivo]

Implemented in commit 2d8f9d5.

What shipped:

API route (workers/api/src/routes/budget.ts)

• GET /v1/budget/limits — returns effective ceilings (4-tier resolution: per-account D1 → platform D1 → env → hard constant), current 24h rolling consumption, distance-to-limit for each ceiling, and which tier each was resolved from.
• PUT /v1/budget/limits — upserts the caller's row in account_budget_limits (tokens and/or charged micros); null / absent = clear override (inherit). Values clamped to MAX_OVERRIDE_* constants. Returns re-resolved effective values.
• Owner-scoped; no new migration (reuses migration 0113 from [backend] Resolve AI budget ceilings from config, not hardcoded constants — env default → per-account override, read in reserve()/openBudget #474).

Console UI (store/console/src/pages/Usage.tsx)

• BudgetPanel component already committed in d951b5f (the [decision] Demote AI budget circuit breakers to observe-only (BUDGET_ENFORCE, default off) — keep structural caps + meter; re-enable at paid launch #485 observe-only commit) — two ceiling gauges (charged spend / tokens), tier label, remaining headroom, and an edit form. Wired to the new route.

Tests (budget.test.ts) — 16 tests: GET defaults, tier resolution (account/platform/default), consumption/remaining, owner scoping; PUT upsert, clamp to MAX, null-on-both deletes row, null-on-one stores NULL, negative/non-numeric rejection, auth.

OpenAPI — GET + PUT /v1/budget/limits documented under the Usage tag; docs:drift at 100%.

Note: per #485, budget enforcement is observe-only (BUDGET_ENFORCE off by default) — the UI and API are live but runs are never blocked by the ceiling until that flag is enabled at paid launch.