Expand and validate DeckMD, the GitHub Pages symptom checker

[deucebucket]

Current release

DeckMD v3.4.0 is live at https://deucebucket.github.io/deckdoc/ as a static, local-only GitHub Pages application with no analytics, account, upload, or external runtime dependency.

The shipped flow starts with six broad categories, nests 12 primary symptoms under them, asks one focused follow-up group at a time, and prunes contradictory paths. The grouped Browse all checks fallback exposes all 128 diagnostic facts. Fifteen evidence-first branches rank the three strongest matches and route into the diagnostic wiki.

Completed

• Deploy reviewed static assets through GitHub Pages with no analytics, account, upload, or external runtime dependency.
• Give every primary symptom connected timing, survivor, scope, environment, behavior, and evidence follow-ups.
• For display symptoms, cover audio, backlight/no-light, input, SSH/streaming, external display, in-game, wake, long-off, second-boot, transition, and model checks.
• Explain why a branch ranked, what evidence to collect, safe next steps, unsafe actions, confidence boundaries, and the relevant wiki route.
• Suppress normal troubleshooting emphasis when a safety-stop answer is selected.
• Return an evidence request instead of guessing when there is no safe match.
• Reject duplicate IDs, missing references, dead wiki routes, uncovered primary symptoms, invalid category nesting, and invalid contradiction rules.
• Validate pointer, keyboard, mobile layout, URL state, advanced search, and contradiction pruning in Firefox/Selenium.
• Add a canonical project version and release-consistency test for Pages copy and repository documentation.
• Deploy v3.4.0 Pages successfully and verify the public version marker.

Remaining scope

• Define a shared, versioned diagnostic vocabulary/schema consumed by the CLI, wiki tooling, and DeckMD so their terms cannot drift.
• Run and record physical Steam Deck LCD/OLED browser checks for Game Mode/Desktop Mode, touch, controller navigation, viewport scaling, and reduced motion.
• Complete a formal accessibility audit covering focus order, screen-reader announcements, contrast, zoom, motion, touch targets, and no-pointer operation.
• Add new rules only from bounded research or sanitized user reports with evidence, confidence, safety, and wiki references.
• Add a maintenance check that flags knowledge entries whose referenced issue/wiki content changes.
• Add application-symptom routes that consume the normalized adapter vocabulary from First-class application diagnostics adapters (RyuDeck baseline) #27.

Non-goals

DeckMD is a triage-priority tool, not probability, medical advice, telemetry, a hardware verdict, or an automatic fixer.