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/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})`);