Queen board: a WIDGETS tab of shareable recordings and players, generated from specs/widgets/gallery.t27 #1373

Problem

t27.ai already has shareable things with pages of their own: 15 terminal recordings of real bench and compiler commands under term/, and the X player that compiles a spec in the reader's browser under play/. Nobody can find them in one place, and none offers embed code. An FPGA engineer who wants to show a colleague "the bitstream is byte-identical to openXC7's" has to dig for the link.

Proposal

Add a WIDGETS view to the Queen board (key v), generated from a .t27 spec:

• specs/widgets/gallery.t27 names the widgets, their shelves (FPGA bench, compiler, agent game) and why each is worth sharing.
• scripts/widgets-from-spec.mjs compiles it with the vendored compiler and runs its test blocks. It reads each widget's own page for its title, description and card, so the gallery cannot claim what the page does not.
• Each card gives the page, a live preview on click, an iframe and a Markdown embed, and X and Telegram share links that open the reader's own composer. Nothing is posted.
• A section lists widgets FPGA engineers use elsewhere in the browser (placement map, resource bars, slack waterfall, bitstream diff, test waveforms, GF16 calculator, race the bee). Each is marked as an idea, not a working widget, with the data it would read.

Acceptance

• npm run check:widgets and npm run test:widgets-spec pass, and run in website-checks.
• A widget whose page is missing, or a cast with a non-zero exit code, fails the build.
• EN and RU copy; no horizontal overflow at 390px.
• The rail key contracts are updated to 1234567890tprbwmlxkgv.

Boundary

apps/website only. No new posting path; no change to any existing view.