Greptile Summary

This PR fixes the "playable" smart collection filter by adding three missing EJS-supported platforms (DOS, GBC, SEGA32) and introducing a new OTHER_SUPPORTED_PLATFORMS list to account for the BROWSER platform (served via Ruffle), which uses a different playback mechanism than EmulatorJS. It also removes a pre-existing duplicate UPS.C64 entry.

• UPS.DOS, UPS.GBC, and UPS.SEGA32 are correctly added to EJS_SUPPORTED_PLATFORMS — all three are confirmed in the frontend's _EJS_CORES_MAP (dosbox_pure, gambatte/mgba, and picodrive respectively).
• OTHER_SUPPORTED_PLATFORMS with UPS.BROWSER is a clean design choice to separate EJS-based emulation from Ruffle-based playback (["flash", "browser"] is the Ruffle-supported check in the frontend).
• UPS.SWANCRYSTAL (swancrystal) appears to be another EJS-supported platform (mednafen_wswan core, same as wonderswan and wonderswan-color) that was not included in this fix and is still absent from EJS_SUPPORTED_PLATFORMS.
• The or_() wrapping of two .in_() calls in _filter_by_playable is functionally correct but could be simplified to a single .in_() with a combined list.

Confidence Score: 4/5

• Safe to merge — changes are additive and logically correct with no risk of regressions.
• All newly added platform slugs (DOS, GBC, SEGA32, BROWSER) are verified to exist in UniversalPlatformSlug and are confirmed as playable in the frontend. The or_() + not_() logic is correct. The only concern is that UPS.SWANCRYSTAL appears to be in the same situation as the platforms this PR fixes but was overlooked.
• No files require special attention beyond the single changed file.

Important Files Changed

Flowchart

%%{init: {'theme': 'neutral'}}%%
flowchart TD
    A[_filter_by_playable called] --> B{value == True?}
    B -- Yes --> C["predicate = or(\n  slug IN EJS_SUPPORTED_PLATFORMS,\n  slug IN OTHER_SUPPORTED_PLATFORMS\n)"]
    B -- No --> D["predicate = not_(or(\n  slug IN EJS_SUPPORTED_PLATFORMS,\n  slug IN OTHER_SUPPORTED_PLATFORMS\n))"]
    C --> E[query.join Platform .filter predicate]
    D --> E

    subgraph EJS_SUPPORTED_PLATFORMS
        F["3DO, AMIGA, ARCADE, ATARI*, C64, DOS ✨\nGBC ✨, SEGA32 ✨, GBA, NES, N64\nNDS, PSX, PSP, GENESIS, SNES, ..."]
    end

    subgraph OTHER_SUPPORTED_PLATFORMS
        G["BROWSER ✨ (Ruffle)"]
    end

    C --> EJS_SUPPORTED_PLATFORMS
    C --> OTHER_SUPPORTED_PLATFORMS

_{Last reviewed commit: 99e41ce}

Okay, I created a OTHER_SUPPORTED_PLATFORMS list since browser games are using Ruffle not EmulatorJS. @zurdi15