fix(docs): [SITE-ROUTES-01] track added HTML without replacing baseline

refactor/scripts/demos.test.mjs

@@ -24,6 +24,7 @@ test('Demo inventory rejects missing files, routes and ecosystem packages', () =
 test('Demo additions require complete paths, specific routes and task ownership', () => {
   const inventory = JSON.parse(fs.readFileSync(path.join(refactorDir, 'baselines/demo-inventory.json'), 'utf8'))
   const additions = JSON.parse(fs.readFileSync(path.join(refactorDir, 'baselines/demo-additions.json'), 'utf8'))
+  assert.doesNotThrow(() => validateDemoInventory(inventory, additions))
   for (const mutate of [
     value => value.examples.pop(),
     value => value.examples.push(value.examples[0]),
@@ -37,3 +38,29 @@ test('Demo additions require complete paths, specific routes and task ownership'
     assert.throws(() => validateDemoInventory(inventory, changed))
   }
 })
+
+test('Added HTML pages retain exact routes, unique paths and accountable introductions', () => {
+  const inventory = JSON.parse(fs.readFileSync(path.join(refactorDir, 'baselines/demo-inventory.json'), 'utf8'))
+  const additions = JSON.parse(fs.readFileSync(path.join(refactorDir, 'baselines/demo-additions.json'), 'utf8'))
+  assert.doesNotThrow(() => validateDemoInventory(inventory, additions))
+  const pending = structuredClone(additions)
+  delete pending.pages[0].introducedBy
+  pending.pages[0].introducedAfter = JSON.parse(fs.readFileSync(path.join(refactorDir, 'tasks.json'), 'utf8')).baselineCommit
+  assert.doesNotThrow(() => validateDemoInventory(inventory, pending), 'A new page can record its pre-change baseline without requiring its own future commit hash')
+  for (const [mutate, error] of [
+    [value => value.pages.pop(), /HTML route coverage drift/],
+    [value => value.pages.push(value.pages[0]), /Duplicate baseline\/addition HTML paths/],
+    [value => value.pages[0].source = 'docs/document/../private.html', /Invalid added HTML path/],
+    [value => value.pages[0].route += '?ignored=1', /Added page route does not match its HTML path/],
+    [value => value.pages[0].owner = 'UNKNOWN-01', /Missing added page owner/],
+    [value => value.pages[0].finalDemoOwner = 'SITE-01', /Missing added page owner/],
+    [value => value.pages[0].introducedBy = '', /Missing page introduction commit/],
+    [value => value.pages[0].introducedAfter = value.pages[0].introducedBy, /Page requires one introduction reference/],
+    [value => delete value.pages[0].introducedBy, /Page requires one introduction reference/],
+    [value => value.pages = false, /Invalid added pages/],
+  ]) {
+    const changed = structuredClone(additions)
+    mutate(changed)
+    assert.throws(() => validateDemoInventory(inventory, changed), error)
+  }
+})