feat(whats-new): remote release notes with dev workspace mode (#1058)

* feat(whats-new): remote release notes with dev workspace mode

Add WHATS_NEW.md, CI whats-new.md asset upload, and client fetch/cache
with embedded fallbacks. Dev and -dev builds read the full file from the
repo for debugging; RC/stable download the release asset on first use.

* fix(whats-new): render ## headings and add changelog tab

Parse h2 sections in release-notes markdown; load changelog alongside
highlights and let users switch views on the What's New page.

* fix(whats-new): prefetch on startup and fix CI typecheck prebuild

Prefetch whats-new asset when the shell loads on RC/stable builds.
Run prebuild:release-notes before tsc and coverage jobs so the
gitignored generated bundle exists in CI.

* docs: CHANGELOG and credits for What's New remote notes (PR #1058)

* fix(whats-new): always slice embedded release notes to current line

Drop full CHANGELOG embed for -dev bundles; tauri:dev still reads live
markdown from the repo. Ignore all of src/generated/ in git.

* fix(whats-new): fetch release asset via Rust to bypass CORS

Route whats-new.md download through fetch_url_bytes; rename the
technical tab label; add fetch unit tests (PR #1058 review).

scripts/extract-release-section.mjs

@@ -0,0 +1,91 @@
+#!/usr/bin/env node
+/**
+ * Extract the body of a ## [version] section from a Keep-a-Changelog-style file.
+ * Resolution matches src/utils/releaseNotes/releaseNotesMatch.ts.
+ *
+ * Usage: node scripts/extract-release-section.mjs <file> <version> [--allow-empty]
+ * Stdout: section body (no ## header). Exit 1 if empty unless --allow-empty.
+ */
+
+import { readFileSync } from 'node:fs';
+import { pathToFileURL } from 'node:url';
+
+const SEMVER_CORE = /^v?(\d+\.\d+\.\d+)/i;
+
+function versionCore(version) {
+  const m = version.trim().match(SEMVER_CORE);
+  return m ? m[1] : null;
+}
+
+function isPlainTriple(header) {
+  return /^\d+\.\d+\.\d+$/.test(header.trim());
+}
+
+function splitBlocks(raw) {
+  return raw.split(/\n(?=## \[)/).filter((b) => b.startsWith('## ['));
+}
+
+function headerVersion(block) {
+  const m = block.match(/^## \[([^\]]+)\]/);
+  return m ? m[1] : null;
+}
+
+function parseBlock(block) {
+  const lines = block.split('\n');
+  const m = lines[0].match(/## \[([^\]]+)\](?:\s*-\s*(.+))?/);
+  if (!m) return null;
+  return {
+    headerVersion: m[1],
+    date: (m[2] ?? '').trim(),
+    body: lines.slice(1).join('\n').trim(),
+  };
+}
+
+export function findReleaseSection(raw, appVersion) {
+  const blocks = splitBlocks(raw);
+
+  const exact = blocks.find((b) => b.startsWith(`## [${appVersion}]`));
+  if (exact) return parseBlock(exact);
+
+  const appCore = versionCore(appVersion);
+  if (!appCore) return null;
+
+  const candidates = blocks.filter((b) => {
+    const hv = headerVersion(b);
+    return hv !== null && versionCore(hv) === appCore;
+  });
+  if (candidates.length === 0) return null;
+
+  const plain = candidates.find((b) => {
+    const hv = headerVersion(b);
+    return hv !== null && isPlainTriple(hv);
+  });
+  return parseBlock(plain ?? candidates[0]);
+}
+
+function main() {
+  const args = process.argv.slice(2);
+  const allowEmpty = args.includes('--allow-empty');
+  const positional = args.filter((a) => a !== '--allow-empty');
+  const [file, version] = positional;
+
+  if (!file || !version) {
+    console.error('Usage: node scripts/extract-release-section.mjs <file> <version> [--allow-empty]');
+    process.exit(2);
+  }
+
+  const raw = readFileSync(file, 'utf8');
+  const entry = findReleaseSection(raw, version);
+  const body = entry?.body?.trim() ?? '';
+
+  if (!body) {
+    if (allowEmpty) process.exit(0);
+    console.error(`No release section found in ${file} for version ${version}`);
+    process.exit(1);
+  }
+
+  process.stdout.write(`${body}\n`);
+}
+
+const isMain = process.argv[1] && import.meta.url === pathToFileURL(process.argv[1]).href;
+if (isMain) main();

scripts/extract-release-section.test.mjs

@@ -0,0 +1,26 @@
+import { describe, it } from 'node:test';
+import assert from 'node:assert/strict';
+import { findReleaseSection } from './extract-release-section.mjs';
+
+const FIXTURE = `
+## [1.48.0] - 2026-06-10
+
+## Highlights
+- One
+
+## [1.47.0]
+- Old
+`;
+
+describe('findReleaseSection', () => {
+  it('matches base line for -rc versions', () => {
+    const entry = findReleaseSection(FIXTURE, '1.48.0-rc.3');
+    assert.equal(entry.headerVersion, '1.48.0');
+    assert.match(entry.body, /Highlights/);
+  });
+
+  it('matches base line for -dev versions', () => {
+    const entry = findReleaseSection(FIXTURE, '1.48.0-dev');
+    assert.equal(entry.headerVersion, '1.48.0');
+  });
+});

scripts/generate-release-notes-bundle.mjs

@@ -0,0 +1,45 @@
+#!/usr/bin/env node
+/**
+ * Build src/generated/releaseNotesBundle.ts for production bundles.
+ * Embeds only the ## [X.Y.Z] slice for package.json version (dev, RC, and stable).
+ * tauri:dev reads live markdown from the repo via Vite ?raw imports instead.
+ */
+
+import { readFileSync, mkdirSync, writeFileSync } from 'node:fs';
+import { dirname, join } from 'node:path';
+import { fileURLToPath } from 'node:url';
+import { findReleaseSection } from './extract-release-section.mjs';
+
+const root = join(dirname(fileURLToPath(import.meta.url)), '..');
+const pkg = JSON.parse(readFileSync(join(root, 'package.json'), 'utf8'));
+const version = pkg.version;
+
+const whatsNewPath = join(root, 'WHATS_NEW.md');
+const changelogPath = join(root, 'CHANGELOG.md');
+const whatsNewFull = readFileSync(whatsNewPath, 'utf8');
+const changelogFull = readFileSync(changelogPath, 'utf8');
+
+function sliceForVersion(full, fileLabel) {
+  const entry = findReleaseSection(full, version);
+  if (!entry?.body) {
+    console.warn(`warn: no section in ${fileLabel} for ${version} — embedding empty slice`);
+    return '';
+  }
+  const dateSuffix = entry.date ? ` - ${entry.date}` : '';
+  return `## [${entry.headerVersion}]${dateSuffix}\n\n${entry.body}`;
+}
+
+const whatsNewRaw = sliceForVersion(whatsNewFull, 'WHATS_NEW.md');
+const changelogRaw = sliceForVersion(changelogFull, 'CHANGELOG.md');
+
+const outDir = join(root, 'src/generated');
+mkdirSync(outDir, { recursive: true });
+
+const ts = `/** @generated — run: node scripts/generate-release-notes-bundle.mjs */
+export const WHATS_NEW_RAW: string = ${JSON.stringify(whatsNewRaw)};
+
+export const CHANGELOG_RAW: string = ${JSON.stringify(changelogRaw)};
+`;
+
+writeFileSync(join(outDir, 'releaseNotesBundle.ts'), ts, 'utf8');
+console.log(`wrote src/generated/releaseNotesBundle.ts (sliced for ${version})`);