Preserve preview harness, editor, email and task improvements

Snapshot current maintainer-preview application changes and regression fixtures for integration into lab. Excludes local runtime data, evaluation outputs and source backups. Focused Python regression selection: 140 passed; full suite not certified.

tests/editorSuggestionButtons.mjs

@@ -0,0 +1,53 @@
+import { readFileSync } from 'node:fs';
+import assert from 'node:assert/strict';
+import { chromium } from 'playwright';
+
+const source = readFileSync('static/js/document.js', 'utf8');
+const start = source.indexOf('  function _showCurrentSuggestion()');
+const end = source.indexOf('  /** Show inline diff by modifying', start);
+assert.ok(start >= 0 && end > start);
+const renderSource = source.slice(start, end);
+
+const browser = await chromium.launch({ headless: true });
+try {
+  const page = await browser.newPage({ viewport: { width: 700, height: 500 } });
+  await page.setContent('<div class="doc-editor-pane"><div id="doc-editor-wrap"></div></div>');
+  await page.addStyleTag({ path: 'static/style.css' });
+  const result = await page.evaluate(code => {
+    let _activeSuggestions = [];
+    let _suggestionTotal = 0, _suggestionIndex = 0;
+    let accepted = [];
+    const _clearSuggestionHighlight = () => {};
+    const topPortalZ = () => 10031;
+    const _clearInlineDiff = () => {};
+    const _clearSuggestionTextSelection = () => {};
+    const _esc = value => String(value || '');
+    const clearAllSuggestions = () => {};
+    const _applySuggestions = suggestions => { accepted = suggestions.map(s => s.id); return accepted; };
+    const _animateNext = () => {};
+    return eval(code + `
+      const inspect = count => {
+        _activeSuggestions = Array.from({length:count}, (_, i) => ({id:String(i),find:'old'+i,replace:'new'+i,reason:'Reason'}));
+        _suggestionTotal = count;
+        _showCurrentSuggestion();
+        const card = document.getElementById('doc-suggestion-active');
+        const buttons = [...card.querySelectorAll('.doc-suggestion-actions button')];
+        const cardRight = card.getBoundingClientRect().right;
+        return {labels:buttons.map(button => button.textContent.trim()),
+          fits:buttons.every(button => button.getBoundingClientRect().right <= cardRight + 1)};
+      };
+      const one = inspect(1);
+      const many = inspect(3);
+      document.querySelector('.doc-suggestion-accept-all').click();
+      ({one, many, accepted});
+    `);
+  }, renderSource);
+  assert.deepEqual(result.one.labels, ['Accept', 'Accept All', 'Skip']);
+  assert.deepEqual(result.many.labels, ['Accept', 'Accept All', 'Skip']);
+  assert.equal(result.one.fits, true);
+  assert.equal(result.many.fits, true);
+  assert.deepEqual(result.accepted, ['0', '1', '2']);
+  console.log('PASS: Accept, Accept All, and Skip stay visible and fit in one row.');
+} finally {
+  await browser.close();
+}