Refresh mutable RAWG metadata for unreleased library games

[dguay]

Problem

RAWG metadata is currently refreshed opportunistically when a game detail query runs. That keeps some release dates fresh when users open a detail page, but it does not reliably update unreleased library games over time.

Mutable fields to account for:

• release_date can move before launch.
• platforms can change as ports/platform announcements are added.
• Rating metadata can move over time, but is lower urgency than release/platform data.

Proposed approach

Add a lightweight refresh path for mutable RAWG metadata on library entries:

• Prioritize want_to_play entries, because release notifications depend on them.
• Refresh entries with missing release data.
• Refresh unreleased/future-dated entries when their RAWG sync timestamp is stale.
• Update both release_date and platforms when refreshing from RAWG.
• Slow down or stop refreshes once a game is known released.
• Treat rating metadata as mutable but lower priority, refreshed on a slower cadence or when opening game detail.

Implementation notes

Possible schema addition:

• library_entries.rawg_metadata_synced_at timestamptz

Possible cadence:

• Missing or future want_to_play: refresh every 12-24 hours.
• Near release window: refresh more frequently if needed.
• Released games: refresh rarely or only on detail open.

This should reduce unnecessary RAWG calls while still keeping release notifications and platform filters accurate for unreleased games.