fix(renovate): the cron fired outside Renovate's own window, so it would never open a PR

.gitea/workflows/renovate.yaml shipped with `cron: "15 3 * * *"`. Gitea Actions
cron is UTC, and renovate.json carries schedule ["after 3am and before 6am"]
with timezone America/New_York -- and THAT inner schedule is authoritative:
Renovate re-checks it and declines to open PRs outside it.

  03:15 UTC  ->  23:15 EDT, the PREVIOUS EVENING in New York
  window     ->  03:00-06:00 local   =>  NOT INSIDE (3h45m early)

The original comment claimed the cron sat "slightly ahead" of the window. It
sat 3h45m behind it, on the previous day. Every nightly run would have started,
logged "not within schedule", opened ZERO PRs and exited SUCCESSFULLY -- a green
tick forever, indistinguishable from "nothing needed updating", hiding the ~30
pending updates PR #73 existed to surface.

Changed to `15 8 * * *`, chosen to survive DST rather than to look tidy:
  EDT (UTC-4): local 03:00-06:00 == 07:00-10:00 UTC
  EST (UTC-5): local 03:00-06:00 == 08:00-11:00 UTC
08:15 UTC is inside BOTH (04:15 EDT / 03:15 EST), verified by computation at
both extremes, so neither switchover needs an edit. A cron cannot follow DST.

Also confirmed while here: RENOVATE_TOKEN now exists as a repo Actions secret,
so the workflow's fail-hard preflight will pass.

STILL UNRESOLVED and the likelier remaining bug: renovate.json's
`enabledManagers` lists bare `regex`, where modern Renovate names the custom
manager `custom.regex`. If the bare name is ignored, every inline `# renovate:`
marker in the tree does nothing. Deliberately NOT changed -- guessing at a key
that could fail validation and take the whole run down is worse than a question
one dry run answers. See the handoff.

Co-Authored-By: Claude Opus 5 (1M context) <[email protected]>

.gitea/workflows/renovate.yaml

@@ -74,12 +74,26 @@ name: renovate
 
 on:
   schedule:
-    # 03:15 UTC daily. renovate.json ALSO carries `"schedule": ["after 3am and before 6am"]` in
-    # America/New_York, and that inner schedule is the authoritative one — Renovate re-checks it and
-    # will decline to open PRs outside it. The two are deliberately both present: this cron decides
-    # when the process RUNS, renovate.json decides when it may ACT. Keeping the cron slightly ahead
-    # of the repo window means a run is always in flight when the window opens.
-    - cron: "15 3 * * *"
+    # 08:15 UTC daily. renovate.json ALSO carries `"schedule": ["after 3am and before 6am"]` with
+    # `"timezone": "America/New_York"`, and THAT inner schedule is authoritative — Renovate re-checks
+    # it and DECLINES TO OPEN PRs outside it. So this cron must fire INSIDE the local window, not
+    # merely near it.
+    #
+    # WAS `15 3 * * *`, WHICH NEVER WOULD HAVE WORKED (fixed 2026-10-18, before the first scheduled
+    # run). Gitea Actions cron is UTC, so 03:15 UTC is 23:15 the PREVIOUS EVENING in New York --
+    # 3h45m BEFORE the window opens, not "slightly ahead" of it as the original comment claimed.
+    # Every nightly run would have started, logged "not within schedule", opened zero PRs and
+    # exited SUCCESSFULLY. A green tick forever, and no updates ever: the exact "failure mode is a
+    # green tick" shape this repo keeps getting burned by, and indistinguishable from "nothing
+    # needed updating".
+    #
+    # THE WINDOW IN UTC MOVES WITH US DST, and a cron cannot follow it:
+    #   EDT (UTC-4, Mar-Nov): local 03:00-06:00 == 07:00-10:00 UTC
+    #   EST (UTC-5, Nov-Mar): local 03:00-06:00 == 08:00-11:00 UTC
+    # 08:15 UTC is the only quarter-hour comfortably inside BOTH (04:15 EDT / 03:15 EST), so the
+    # schedule keeps working across both switchovers without an edit. Do not "tidy" this back to an
+    # early-morning-UTC value without redoing this arithmetic.
+    - cron: "15 8 * * *"
   workflow_dispatch:
     inputs:
       dry_run: