Document ctx.date.nowMillis() in both plugin API references

🤖 Generated with [Claude Code](https://claude.ai/code)

Co-Authored-By: Claude <noreply@anthropic.com>

Author: pwnqgljxs

docs/plugin-prototype.md

@@ -120,6 +120,8 @@ built-ins, but no browser or Node host environment. Tests assert that `fetch`, `
   positive and capped at 24 hours.
 - `ctx.date.now()`, `iso(text)`, `unixSeconds(number)`, and `unixMillis(number)` return JavaScript `Date` objects.
   `now()` uses the host refresh clock so fixtures and retries share the snapshot timestamp.
+- `ctx.date.nowMillis()` returns that same refresh clock as Unix epoch milliseconds for deterministic date arithmetic
+  (used by the z.ai quota-rate row).
 - `ctx.date.nextDailyReset(timeZoneIdentifier, hour)` returns the next wall-clock hour in an IANA time zone, including
   DST transitions. Crof uses `America/Chicago` at hour `0`.
 - `ctx.jwt.decode(token)` decodes the JSON payload segment without verifying a signature.

docs/plugins.md

@@ -106,6 +106,8 @@ so portable third-party plugins must use the host helpers below instead of ECMA-
   24 hours.
 - `ctx.date.now()`, `iso(text)`, `unixSeconds(number)`, and `unixMillis(number)` create JavaScript dates. `now()` uses
   the host refresh clock.
+- `ctx.date.nowMillis()` returns the same host refresh clock as Unix epoch milliseconds — use it for arithmetic that
+  should stay deterministic under fixture clocks (the z.ai quota-rate row does).
 - `ctx.date.nextDailyReset(timeZoneIdentifier, hour)` returns the next wall-clock reset in an IANA time zone.
 - `ctx.env.timeZone` is the host's current IANA time-zone identifier; zero-offset GMT aliases are normalized to `UTC`.
 - `ctx.format.number(value, options?)`, `usd(value)`, and `monthDay(date)` provide deterministic formatting on both