gardener: kind tabs + user-selectable pagination for the findings page (default 25)

[genwave-radio]

🧭 Ask (Dean)

• Break the five kind sections into tabs — no one is scrolling past 200+ near-duplicate entries to reach the next section.
• User-selectable page size with a sane default: start at 25, offer 50 / 100 / 250 (final option set at /design) — not the current one-shot 1000.

🔎 Context

• Replaces GardenerView's single ?state=open&limit=1000 flat fetch with a per-kind, paged fetch — the API already supports kind=, limit=, offset=, and /api/status gardener.open carries the real per-kind totals for tab badges + pager math.
• Structurally fixes gardener: flat 1000-row findings page ordered by kind starves every later kind to zero rows #654 (per-kind fetch ends the kind starvation) and retires the "Showing first N of M" caveat.
• Prior art: reuse admin-ui/components/ui/tab-strip.tsx (extracted in the kind-folders sweep). Near-duplicate group cards must not be split mid-group by a page boundary — page on groups, not rows, for that tab (design call).

[genwave-radio]

📐 Designed 2026-08-31 (SPEC F153.9/F153.10 riders + ARCHITECTURE key-decisions block). Rulings:

• Page rebuilds on the catalog idiom: server-rendered, URL-driven ?tab=&page=&limit=, TabStrip, plain-anchor pager, verbs via router.refresh() — the client-fetched GardenerView LoadState retires.
• Page size: default 25, picker 25 / 50 / 100 / 250, ?limit= only (no localStorage stickiness — rejected).
• Near-duplicates tab pages by GROUP: limit/offset count distinct group_keys, a page never splits a cluster.
• Kind-scoped GET /api/gardener/findings gains total (groups for near_duplicate, rows otherwise) for "page N of M"; un-scoped calls keep the T377 shape verbatim. Tab badges keep reading /api/status.gardener.open.
• Fixes gardener: flat 1000-row findings page ordered by kind starves every later kind to zero rows #654 structurally; "Showing first N of M" caveat retires.

Next: /plan.

[genwave-radio]

Shipped via #658 + #659 (phase G-h, T385–T387): kind tabs, per-tab pagination (default 25, picker 25/50/100/250, URL-only), group-paged near-duplicates with exact totals. #654 closed with it. Ships in v5.5.1.