Make the platform conformance ledger scannable by default

[rmcdaniel]

Problem

The public /docs/platform-conformance/ discovery page renders both authority catalogs and every exact-tuple experiment table expanded by default. With the current 29-experiment ledger, the live document is roughly 25,000 pixels tall at desktop width and 30,000 pixels tall on mobile. The current tuple and per-tier summary are present and correct, and the full machine-readable ledger is already available as JSON, but a human reader must traverse a long wall of detailed rows to reach later guidance.

Acceptance criteria

• Keep the ledger snapshot time, retained-evidence capture time, current artifact tuple, per-tier state, evidence counts, runner-blocked count, and product-failure count immediately readable in the default page flow.
• Put detailed per-experiment rows behind accessible per-tier progressive disclosure or dedicated linked detail views while keeping every experiment and evidence link available.
• Preserve meaningful deep links and keyboard and screen-reader access to expanded detail.
• Keep /platform-conformance/run-ledger.json as the complete machine-readable authority; the presentation change must not weaken or duplicate its contract.
• Validate default and expanded states at desktop, intermediate, mobile, and short-height viewports with no horizontal overflow, clipped text, unreachable controls, overlap, or browser errors.
• Validation may assert information availability, accessibility, interaction, and responsive behavior, but must not freeze prose wording, exact headings, paragraph order, or Markdown layout.

Delete when

Delete when the human discovery page presents the current tuple and tier summary without expanding all experiment detail by default, every experiment remains accessible on demand or through a focused route, and responsive interaction evidence covers both collapsed and expanded states.