Merged-page review fixes: exclude flagged rows, wire comparability, thread card

Merged pages: restore full eval-page plots by mounting EvalDetail at merged grain

Fix embeds and duplicates

Fix embeds to filter by canonical benchmark only (no splits in embed until we decide how to display splits) + suppress popup on embed routes

Update embeds title and move toggle order

view-data: coerce BIGINT-encoded numeric strings; restore distribution embed route

Untrack accidentally-committed noise files; gitignore the patterns

view-data: paranoid CAST every output column to a primitive type

Embeds: histogram route, leaderboard slices + sort, brand mark; cross-source row dedup