Adds an N-tool for list/table footer pagination: row of page-
number pills flanked by optional prev/next chevron buttons. Active
page renders filled with the accent color, inactive pages are
ghost. Long ranges collapse with "…" Google-style (always show 1
and total, plus a ±siblings window around current).
Wired through all 3 paths: pen-core buildPagination + pen-mcp
handler + apps/web browser shim + Nitro SERVER_BUILDERS. Both
parity tests (shim-server-parity, element-tool-registry-parity)
pick up the entry automatically. Handler test covers 7 cases:
small range no ellipsis, 10-page ellipsis, start-edge current,
accent override, show_arrows=false, total=1 single pill, bogus
parent_id rejection.
Also updates packages/pen-ai-skills/skills/phases/generation/
elements.md: decision tree §52, keyword triggers (pagination /
page nav / 分页 / 分页条), minimal usage example. The stale-
integration guard (design-prompt-elements.test.ts) now passes.