intake: widen the dashboard into the Mind's task page, and make it checkable

[Jammy2211]

Rewrites the intake dashboard renderer so PyAutoMind/dashboard.md is a page a human can pick work from, on GitHub web or a phone. Paired with PyAutoLabs/PyAutoMind#182, which links the page from the Mind's README and adds the CI that keeps it fresh.

Merge this first. The Mind workflow calls _intake.py … dashboard --check, which only exists after this lands.

Why

The page was a backlog inventory: ten five-column tables, 133 rows, no in-flight work and no issue links. It answered "how many prompts are there?" for someone already at a terminal. The page a human opens on GitHub — often on a phone — has to answer "what should I pick up now?", and a five-column table with 39 rows scrolls sideways on a phone rather than wrapping.

What changed

• Picks first. The page opens with ## Start here: highest-priority prompts (sorted smallest-first) and quick wins (small and safe-autonomy). Then in flight, parked, planned, and the full backlog behind <details>.
• Bullets, not tables. Every prompt row is a bullet with its facets after an em dash. The only table left is the 2-column where/count summary.
• The registry is now in the census. census() parses active.md / parked.md / planned.md into rows, so the page covers what has left the backlog, not just what sits in it.
• Issue links come from the registry row that names the prompt, never from a URL in the prompt body — a body URL is as often a cross-reference as the task's own issue. For the same reason in-flight rows show the registry's status, not the prompt's own Status: header, which reads formalised from conception until the day it ships.
• Live GitHub links for the half a static file cannot hold: org-wide open issues and PRs.
• dashboard --check exits 1 when the committed page has drifted, ignoring the generation stamp so a re-render on an unchanged Mind is not drift (otherwise the Mind's self-heal would commit daily).

Rendering safety

Pinned by tests because these failures are silent rather than loud:

• a prompt titled with a leading <!-- (the untriaged ones are) commented out the rest of the page in GitHub's renderer;
• a [JAX] in a title ended its markdown link early;
• an issue: field with trailing prose (…/issues/20 (build gated)) linked the prose into the URL.

Testing

tests/test_intake_dashboard.py — 10 hermetic tests over fictional Minds in tmp_path, covering pick ordering, the quick-wins filter, the bullet/<details> shape, registry-vs-header status, the no-registry-row case, both rendering hazards above, and --check drift-vs-calendar.

Full suite: 349 passed. bin/check_skill_line_counts.sh clean.

Docs

agents/conductors/intake/AGENTS.md (verb table + examples) and skills/intake/intake.md updated to describe the task page and --check.