fix(renovate): widen lockFileMaintenance schedule so it actually fires (#45)

The lockFileMaintenance schedule was "before 7am on Monday/Thursday"
(UTC, ~00:00-07:00). Mend's hosted Renovate scan cadence never lands in
that narrow pre-dawn window, so lockFileMaintenance has never produced a
PR for any consumer (e.g. nix-devenv flake.lock sat untouched for 17+
days despite the twice-weekly schedule).

Align it with the wide "after 7am on Monday/Thursday" window already used
by the custom-regex managers in this same preset: still twice-weekly, but
a ~17h window Mend reliably hits.

Assisted-by: Claude:claude-opus-4-8
Claude-Session: https://claude.ai/code/session_01FGPtj4jnggZYA53EkTXbTA

Author: JacobPEvans-personal

renovate-presets.json

@@ -44,8 +44,8 @@
   "lockFileMaintenance": {
     "enabled": true,
     "schedule": [
-      "before 7am on Monday",
-      "before 7am on Thursday"
+      "after 7am on Monday",
+      "after 7am on Thursday"
     ],
     "automerge": true,
     "minimumReleaseAge": "0 days"