docs(sdlc): write each work product as of its own date

- SOW, plan and design no longer cite the Aug baseline commit or the package tag
- Work Schedule status derived from its date; Test Case has no results yet
- build fails when a document cites a later commit, tag, ISS or ID (timeline.mjs)

Co-Authored-By: Claude Opus 5.5 (1M context) <noreply@anthropic.com>

scripts/sdlc-seed/build.mjs

@@ -8,6 +8,7 @@ import * as pm2 from './docs-pm2.mjs';
 import * as si from './docs-si.mjs';
 import * as si2 from './docs-si2.mjs';
 import * as other from './docs-other.mjs';
+import { hindsightErrors } from './timeline.mjs';
 
 const root = path.resolve(path.dirname(fileURLToPath(import.meta.url)), '../..');
 const target = path.join(root, 'sdlc');
@@ -70,6 +71,9 @@ async function main() {
     if (!FOLDERS.includes(d.dir)) throw new Error(`Unknown folder for ${d.name}: ${d.dir}`);
   }
 
+  const hindsight = hindsightErrors(docs, root);
+  if (hindsight.length) throw new Error(`Work products cite things that did not exist yet on their date:\n- ${hindsight.join('\n- ')}`);
+
   await fs.rm(target, { recursive: true, force: true });
   for (const folder of FOLDERS) await fs.mkdir(path.join(target, folder), { recursive: true });
   for (const d of docs) {