feat(miner-ui): add portfolio/queue summary cards view

[JSONbored]

Depends on the apps/gittensory-miner-ui/ scaffold (sibling Phase 6 issue) landing first.

The data source is packages/gittensory-miner/lib/portfolio-queue.js's miner_portfolio_queue table: one row per (repo_full_name, identifier) with a priority, a status constrained to queued | in_progress | done, and enqueued_at (portfolio-queue.js:12,89-98) — already exposed via listQueue(repoFullName?) (:151-156). This view is summary cards (counts by status, optionally grouped by repo) over that existing store — no new persistence, no new ranking logic, purely a read + aggregate over what listQueue() already returns.

Deliverables

• Summary cards showing queue counts by status (queued / in_progress / done), and per-repo breakdowns if the cross-repo case (multiple repos in one local queue) is common enough to warrant it — portfolio-queue.js's schema already supports filtering by repoFullName.
• Read-only: the view aggregates listQueue()'s output client-side (or via the same local data-access layer the run-history view, sibling issue, introduces) rather than adding new queue-store methods, unless a dedicated summarize()-style helper turns out cleaner — if so, add it to portfolio-queue.js itself rather than duplicating the aggregation in the UI layer.
• Empty-state handling for a fresh install with no queued items yet.
• Component/unit tests given a fixture set of queue rows across the three statuses.

References

• packages/gittensory-miner/lib/portfolio-queue.js:12,89-98,151-156 — the miner_portfolio_queue schema, statuses, and existing listQueue accessor this view summarizes.
• Sibling Phase 6 issue: feat(miner-ui): scaffold apps/gittensory-miner-ui/ dashboard shell — hard dependency.
• Sibling Phase 6 issue: feat(miner-ui): add read-only run-history table view — likely shares the same local data-access layer.

[linear-code]

JSO-3293