* launcher: keep primary update feed answer when the fallback request fails
When the primary feed is reachable but its tag differs from the build tag,
the result was discarded and the GitHub API fallback was consulted. If the
fallback request failed (api.github.com rate-limits unauthenticated
requests), the launcher reported an error even though the primary feed had
already returned a usable update answer with a working release URL. Keep
the primary feed answer and show it if the fallback fails.
* emulator: validate numeric CLI arguments
--screen-width, --screen-height, --gpu, and --vblank-frequency were parsed
with Common::ToInt32/ToInt64, which ignores std::from_chars errors and
returns 0, so values like "--screen-width abc" or "--gpu xyz" were
silently accepted: zero screen size, or GPU 0 selected instead of auto
(-1). Reject invalid values with an error message like the other options,
using from_chars-based helpers (ParseUint32/ParseInt32); reject zero
screen dimensions.
* tests: add LeastRecentlyUsedCache regression tests
Cover the LRU cache walk order, tick filtering in ForEachItemBelow,
early-exit boolean callbacks, Touch reordering and same-tick skips,
Free, and freed-id reuse by later inserts. Modeled on BitArrayTests.
* tests: use a tick cutoff that detects a stale newest-item tick
Collect(cache, 35) also visits c when Touch(c, 35) failed to update
its tick (30 <= 35). Use a cutoff of 30 and expect only b.
* Run LRU cache tests in CI
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Co-authored-by: nmzik <Nmzik@mail.ru>
Saadi