fix(espn): fetch a window's edge months whole, cap chunk requests per process (#751)

- fetch_espn_date_chunks() asks for a window's partial edge month whole when the window covers ESPN_MONTH_COVER_MIN_DAYS (7) or more of its days, trimmed to the window by US Eastern start date. New espn_request_chunks().
- Chunk requests share one process-wide cap of ESPN_CHUNK_WORKERS (6) in flight.
- A new process starts as if a range had just been rejected, so it no longer spends a doomed 400 per window at start.
- Also: _eastern_zone() without try/except/pass (Codacy), and test_on_demand_live_and_restore reads the last on-demand state write rather than the last cache write (the font-usage publisher raced it; main CI had failed on it since #748).

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

CHANGELOG.md

@@ -34,6 +34,29 @@ accepts both, but the store flags the old spelling as deprecated
   once the interval has passed. The cadence is unchanged, and nothing extra
   runs when no frame is owed.
 
+### ESPN date-range fetches: fewer requests, fewer at once
+
+A soccer board (8 leagues, ESPN rejecting `dates=` ranges) logged ~90
+`NameResolutionError` lines and an `update() timed out` at every start on a
+Pi: each league's fortnight-either-side window was 29 day requests, fetched
+by several managers at once, ~40 in flight. Measured against live ESPN with
+soccer-scoreboard 2.39.2, alternating runs: **~450 requests per start, peak
+~45 in flight, ~75 DNS lookups -> 46 requests, peak 13, ~30 lookups**.
+
+- `fetch_espn_date_chunks()` asks for a window's partial edge month whole
+  when the window covers `ESPN_MONTH_COVER_MIN_DAYS` (7) or more of its days,
+  and trims the answer to the window's days by each event's US Eastern start
+  date -- the day ESPN's `dates=YYYYMMDD` means (417 of 417 live soccer
+  events matched). A 29-day window spanning two months is 2 requests instead
+  of 29. Short windows (a live poll's 1-2 days) stay day by day. A trimmed
+  month that comes back at the 500-event cap re-asks only the window's days.
+  An event with no readable date is kept. New: `espn_request_chunks()`.
+- Chunk requests share one process-wide cap of `ESPN_CHUNK_WORKERS` (6) in
+  flight, across every window being fetched, instead of six per window.
+- A new process starts as if a range had just been rejected, so it no longer
+  spends one doomed 400 per window at every start (eleven at once from a
+  soccer board); the range is still retried `RANGE_RETRY_SECONDS` in.
+
 ### Cheap per-frame and per-fetch savings
 
 - `BaseOddsManager.get_odds()` no longer pretty-prints every odds response