Learn, per user tag, which auto TOPIC tags are characteristic of the channels
you've tagged it, then suggest that tag for still-untagged subscribed channels
whose topics cover enough of the profile. Language auto-tags are excluded from
the signal — near-universal within a language, they flooded every channel.
New GET /api/tags/suggestions (read-only, deterministic) backed by
app/sync/tagsuggest.py. Surfaced in the Channel Manager as dashed "ghost" chips
in the tags cell — one tap accepts (reuses the attach-tag endpoint), × dismisses
for the session — plus a header badge and a bulk "Accept N confident" (the
full-profile matches) behind a confirm. No silent writes (D4 = suggest-and-confirm).
Also reflow a pre-existing prettier drift in dateFilter.ts from E8·S2.