fix(sports): recover from ESPN rejecting scoreboard date ranges (#591)

* fix(sports): recover from ESPN rejecting scoreboard date ranges

Since 2026-09-15 ESPN's site API answers `dates=YYYYMMDD-YYYYMMDD` with
400 "Failed to get events endpoint." for every sport. Single days, months
(`YYYYMM`) and season years still work. Every season and weeks-window fetch
in core failed, including the background service the scoreboards submit
their season schedules to.

src/common/espn_dates.py re-asks a rejected range as whole-month chunks
plus the leftover edge days, which tile the window exactly (a season is
8 requests, not 213). A month that comes back with exactly 500 events is
truncated (college baseball's March) and is re-asked day by day.

It also clamps `limit` to 500: above that ESPN truncates silently, e.g.
college football returns 25 of 68 games for one Saturday at limit=1000.

BackgroundDataService recovers rejected ranges on the worker thread and
advertises `handles_espn_date_ranges` so plugins can tell whether to hand
it a range. SportsCore, sports_shared, ESPNDataSource and APIHelper route
through the helper or the clamped limit.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>

* docs(changelog): ESPN date-range fallback and limit clamp

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>

* fix(sports): stop re-sending ESPN date ranges once one is rejected

Live scoreboards refresh every 30 seconds, and each refresh sent the range
first, got the 400, then fetched the chunks: three requests where one used
to do. After a rejection, ranges now go straight to chunks for six hours,
then the range is tried again so the workaround retires itself if ESPN
reverts. A single-day 400 does not set the memo, and when every chunk fails
the range request supplies the error without the chunks being fetched a
second time. Per-fetch chunk logging drops to debug; the rejection itself
stays a warning.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>

* fix(sports): clamp limit only on ESPN scoreboard submissions

The background service is generic, and limit above 500 only truncates
scoreboards. /teams needs limit=1000 (college football has 762 teams and
limit=500 returns 500), so a teams submission must keep its limit.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>

---------

Co-authored-by: Claude Opus 5 <noreply@anthropic.com>

CHANGELOG.md

@@ -38,6 +38,26 @@ this):
 - `test/test_common_is_hardware_free.py` — `src/common` must import without
   `rgbmatrix` and never import `src.base_classes`, `src.display_manager` or
   `src.plugin_system` at module level.
+- `src/common/espn_dates.py` — `fetch_espn_scoreboard`,
+  `fetch_espn_date_chunks`, `espn_date_chunks`, `clamp_espn_limit`,
+  `ESPN_MAX_LIMIT`: fetch an ESPN scoreboard date range now that ESPN rejects
+  ranges (see Sports data below). Plugins bundle a copy of it.
+
+Sports data:
+
+- Since 2026-09-15 ESPN answers `dates=YYYYMMDD-YYYYMMDD` scoreboard queries
+  with `400 Bad Request` for every sport, so season schedules, the weeks window
+  and today's games all failed ("400 Client Error" from the NFL/NCAAFB managers
+  and `src.background_data_service`). A rejected range is now re-fetched as
+  whole months (`dates=YYYYMM`) plus the leftover days at each end, which cover
+  the window exactly: a football season is 8 requests. A month that returns
+  exactly 500 events is truncated and is re-fetched day by day.
+- Scoreboard requests send `limit=500` at most. Above 500 ESPN silently returns
+  a short list: college football gave 25 of 68 games for one Saturday at the
+  `limit=1000` everything used to send.
+- `BackgroundDataService.handles_espn_date_ranges` is `True`. Plugins check it
+  to decide whether to submit a season range to the service or fetch it
+  themselves on an older core.
 
 Web interface: