Context-meter amendment: CONTEXT_LIMITS dies — pi's live catalog is the only limit source

Owner ruling (2026-09-23, amendment to 04e336d): no hardcoded fallback
exists anywhere. contextWindow(record, limits) resolves the denominator
ONLY from the live index (provider:id -> contextWindow straight from
pi's catalog); a model missing from it (historical session, package
update, failed fetch) reads limit null and the meter renders
usage-only — the honest-render precedent, never a fake window.

- src/core/prices.ts: the 1354-entry CONTEXT_LIMITS table (65KB) and its
  generation apparatus deleted; the fold returns limit: number | null.
  PRICES untouched (regen verified byte-identical via the reworked
  sync-pricing script).
- scripts/sync-pricing.ts: generates PRICES only; contextWindow leaves
  the priced map, the guard, and the template.
- The dock meter's owner-selected treatment: the activity feed carries
  the limit server-side. catalogContextLimits() (server/model-catalog.ts)
  builds the index over the same keyed providers the picker federates;
  activityFeed() joins it onto every running job (ActivityJob.contextLimit,
  null when the model is missing — the dock reads it off the feed, no
  client-side table, no regression while the UI's catalog-join chunk lands).
- components/activity-dock.tsx: toBlobs reads job.contextLimit (import
  of CONTEXT_LIMITS gone); stats-bar renders usage-only on null limit
  (mechanical interim — UI stream's join chunk follows).
- tests: usage.test.ts pins the no-fallback contract (index hit / absent
  / empty / missing-model -> null); activity-feed.test.ts pins the
  server join (catalog model -> 1048576, unknown -> null, no-usage ->
  null); render pins updated to the interim usage-only render.

src/core/contracts/jobs.ts

@@ -53,9 +53,11 @@ export interface JobUsage {
 	/** How many model calls the run has made (each bills separately). */
 	steps: number;
 	/** The MOST RECENT model call's accounting (2026-09 dock contract): the
-	 * per-blob context line reads last-step input+output against the model's
-	 * CONTEXT_LIMITS — never the cumulative totals. Absent until the first
-	 * call completes; absent provider fields stay absent (never zero). */
+	 *  per-blob context line reads last-step input+output against the
+	 *  model's LIVE catalog limit (server-joined onto the activity feed —
+	 *  never the cumulative totals, never a client-side table). Absent
+	 *  until the first call completes; absent provider fields stay absent
+	 *  (never zero). */
 	lastStep?: CallUsage;
 }