Add collaborative alt text export guard

collaborative-alt-text-export-guard/.gitignore

@@ -0,0 +1 @@
+reports/frames/

collaborative-alt-text-export-guard/README.md

@@ -0,0 +1,36 @@
+# Collaborative Alt Text Export Guard
+
+This module is a self-contained accessibility export-readiness slice for the SCIBASE real-time collaborative research editor bounty.
+
+It focuses on publication content accessibility, not editor control accessibility. Before a collaborative manuscript is exported, it checks whether figures and tables have current, non-private, scientifically useful alt text, long descriptions, table header metadata, and accessibility sign-off.
+
+## What It Checks
+
+- Missing or generic alt text for exportable figures and tables
+- Alt text that only repeats the caption
+- Complex visuals that need a long description or data summary
+- Color-only encodings without non-color labels or patterns
+- Table headers, scopes, and summaries for screen-reader navigation
+- Stale alt text after collaborative edits or source-data changes
+- Open blocking accessibility comments
+- Alt text changes inside locked final-review sections without approval
+- Leaks of private reviewer notes, local file paths, or protected data markers
+
+## Files
+
+- `index.js` exports the evaluator plus Markdown/SVG renderers.
+- `sample-data.js` contains clean, revision-required, and hold-required synthetic packets.
+- `test.js` covers the release decisions and high-risk findings.
+- `demo.js` writes JSON, Markdown, and SVG reviewer artifacts under `reports/`.
+- `make-demo-video.js` writes a short local `reports/demo.mp4` artifact with the three decisions.
+
+## Local Verification
+
+```sh
+npm run check
+npm test
+npm run demo
+npm run verify-video
+```
+
+No production credentials, private data, external APIs, or package installs are required.

collaborative-alt-text-export-guard/demo.js

@@ -0,0 +1,38 @@
+"use strict";
+
+const fs = require("node:fs");
+const path = require("node:path");
+const {
+  evaluateAccessibleExportPacket,
+  renderMarkdownReport,
+  renderSvgSummary
+} = require("./index");
+const { cleanPacket, revisionPacket, holdPacket } = require("./sample-data");
+
+const reportsDir = path.join(__dirname, "reports");
+fs.mkdirSync(reportsDir, { recursive: true });
+
+const scenarios = [
+  ["clean", cleanPacket],
+  ["revision", revisionPacket],
+  ["hold", holdPacket]
+];
+
+const manifest = scenarios.map(([name, packet]) => {
+  const result = evaluateAccessibleExportPacket(packet, {
+    now: "2026-06-01T10:15:00.000Z"
+  });
+  fs.writeFileSync(path.join(reportsDir, `${name}-report.md`), renderMarkdownReport(result));
+  fs.writeFileSync(path.join(reportsDir, `${name}-summary.svg`), renderSvgSummary(result));
+  fs.writeFileSync(path.join(reportsDir, `${name}-result.json`), `${JSON.stringify(result, null, 2)}\n`);
+  return {
+    scenario: name,
+    decision: result.decision,
+    exportAllowed: result.exportAllowed,
+    findings: result.findings.length,
+    digest: result.digest
+  };
+});
+
+fs.writeFileSync(path.join(reportsDir, "manifest.json"), `${JSON.stringify(manifest, null, 2)}\n`);
+console.log(JSON.stringify(manifest, null, 2));