Three UAT refinements on the tag cell + popover platform:
- Fixed tag-column width (w-[15rem], was max-w): under table-layout:auto a content-
driven cell re-solved every column's width on each chip added, so the table visibly
shifted (and the "+N" count flickered) until the cap was hit. A fixed footprint makes
adding/removing tags move nothing (verified: column x unchanged, "+N" count stable).
- No popover flash: gate the floating surface's visibility on Floating UI's isPositioned
so it never paints at (0,0) top-left for a frame before the transform lands.
- Sync cell no longer wraps: flex-nowrap so the recent/full badges stay on one line
(the column grows to fit them instead of breaking to two rows).