docs: renewed README and light/dark diagonal screenshots; wider hashtag tiles

- README: current features (journal, focus mode, push, themes, sharing
  into the inbox), outgoing connections, :latest instead of :stable,
  VAPID_* and LEGAL_CUSTOM_LINK_*, new journal and phone screenshots
- e2e/screenshots.sh: light and dark in the same state joined along a
  diagonal, own container/port per run
- hashtag tiles at least 18rem wide

chore(release): v0.15.0

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

e2e/screenshots.mjs

@@ -1,9 +1,15 @@
 // Takes the README screenshots from a fresh server in demo mode (sample data of admin/admin).
+// Every picture is taken twice in the same state – light and dark theme – and the two halves are
+// joined along a slanted diagonal (light left, dark right).
 // Usage: e2e/screenshots.sh (builds the image) or MINDSIFT_URL=… SHOTS_DIR=… node screenshots.mjs
+// Theme pair: SHOT_LIGHT / SHOT_DARK (default: light / dark, the "Klassik" family)
+import fs from 'node:fs';
 import { chromium } from 'playwright';
 
 const BASE = process.env.MINDSIFT_URL || 'http://localhost:18080';
 const OUT = process.env.SHOTS_DIR || '../screenshots';
+const LIGHT = process.env.SHOT_LIGHT || 'light';
+const DARK = process.env.SHOT_DARK || 'dark';
 const DESKTOP = { viewport: { width: 1518, height: 886 }, deviceScaleFactor: 2 };
 const MOBILE = { viewport: { width: 390, height: 844 }, deviceScaleFactor: 2, isMobile: true, hasTouch: true };
 const sleep = (ms) => new Promise((r) => setTimeout(r, ms));
@@ -20,7 +26,13 @@ async function login(user) {
 
 async function open(browser, token, options) {
   const ctx = await browser.newContext({ ...options, colorScheme: 'dark', locale: 'de-DE' });
-  await ctx.addInitScript((t) => localStorage.setItem('mindsift_jwt_token', t), token);
+  await ctx.addInitScript(
+    ([t, theme]) => {
+      localStorage.setItem('mindsift_jwt_token', t);
+      localStorage.setItem('mindsift_active_theme', theme);
+    },
+    [token, DARK]
+  );
   const page = await ctx.newPage();
   page.on('pageerror', (e) => console.log('PAGEERROR', e.message));
   await page.goto(BASE);
@@ -28,12 +40,76 @@ async function open(browser, token, options) {
   return page;
 }
 
-const tab = (page, name) => page.getByRole('button', { name: new RegExp(name) }).first().click();
+// Anchored, so "Workspace" does not hit the triage button "Als Notiz – Im Workspace"
+const tab = (page, name) => page.getByRole('button', { name: new RegExp(`^${name}`) }).locator('visible=true').first().click();
+
+// Switches the theme in place (no reload), so both halves show exactly the same state
+async function setTheme(page, id, dark) {
+  await page.evaluate(
+    ([themeId, isDark]) => {
+      const root = document.documentElement;
+      root.setAttribute('data-theme', themeId);
+      root.classList.toggle('dark', isDark);
+    },
+    [id, dark]
+  );
+  await sleep(250);
+}
+
+let composer;
+// Light picture on the left of the diagonal, dark on the right, a thin line between them
+async function compose(lightPng, darkPng, file) {
+  const dataUrl = await composer.evaluate(
+    async ([light, dark]) => {
+      const load = (b64) =>
+        new Promise((resolve) => {
+          const img = new Image();
+          img.onload = () => resolve(img);
+          img.src = 'data:image/png;base64,' + b64;
+        });
+      const [a, b] = await Promise.all([load(light), load(dark)]);
+      const w = a.naturalWidth;
+      const h = a.naturalHeight;
+      const canvas = document.createElement('canvas');
+      canvas.width = w;
+      canvas.height = h;
+      const ctx = canvas.getContext('2d');
+      ctx.drawImage(b, 0, 0);
+      const top = w * 0.58;
+      const bottom = w * 0.42;
+      ctx.save();
+      ctx.beginPath();
+      ctx.moveTo(0, 0);
+      ctx.lineTo(top, 0);
+      ctx.lineTo(bottom, h);
+      ctx.lineTo(0, h);
+      ctx.closePath();
+      ctx.clip();
+      ctx.drawImage(a, 0, 0);
+      ctx.restore();
+      ctx.strokeStyle = 'rgba(255, 255, 255, 0.9)';
+      ctx.lineWidth = Math.max(2, w / 600);
+      ctx.shadowColor = 'rgba(0, 0, 0, 0.35)';
+      ctx.shadowBlur = w / 300;
+      ctx.beginPath();
+      ctx.moveTo(top, 0);
+      ctx.lineTo(bottom, h);
+      ctx.stroke();
+      return canvas.toDataURL('image/png');
+    },
+    [lightPng.toString('base64'), darkPng.toString('base64')]
+  );
+  fs.writeFileSync(`${OUT}/${file}`, Buffer.from(dataUrl.split(',')[1], 'base64'));
+}
 
 async function shot(page, file) {
   await sleep(800); // animations
   await page.mouse.move(0, 0);
-  await page.screenshot({ path: `${OUT}/${file}` });
+  await setTheme(page, LIGHT, false);
+  const light = await page.screenshot();
+  await setTheme(page, DARK, true);
+  const dark = await page.screenshot();
+  await compose(light, dark, file);
   console.log(`OK   ${file}`);
 }
 
@@ -41,6 +117,7 @@ const main = async () => {
   const admin = await login('admin');
   const user = await login('user');
   const browser = await chromium.launch({ args: ['--lang=de-DE'] });
+  composer = await (await browser.newContext()).newPage();
 
   const page = await open(browser, admin, DESKTOP);
   await tab(page, 'Triage');
@@ -67,6 +144,36 @@ const main = async () => {
   await sleep(2000);
   await shot(page, 'workspace_desktop.png');
 
+  // Journal: a few days with entries, the calendar in the sidebar
+  const H = { Authorization: `Bearer ${admin}`, 'Content-Type': 'application/json' };
+  const today = new Date();
+  const iso = (d) => `${d.getFullYear()}-${String(d.getMonth() + 1).padStart(2, '0')}-${String(d.getDate()).padStart(2, '0')}`;
+  const day = (offset) => iso(new Date(today.getFullYear(), today.getMonth(), today.getDate() - offset));
+  await fetch(`${BASE}/api/v1/journal/${day(0)}`, { method: 'POST', headers: H });
+  await page.getByRole('button', { name: 'Journal', exact: true }).click();
+  await sleep(1500);
+  const write = async (date, lines) => {
+    const section = page.locator(`[data-journal-date="${date}"]`);
+    if ((await section.count()) === 0) return; // day outside the visible month
+    await section.locator('.cursor-text').first().click();
+    for (let i = 0; i < lines.length; i++) {
+      if (i > 0) await page.keyboard.press('Enter');
+      await page.keyboard.type(lines[i], { delay: 5 });
+    }
+    await sleep(600);
+  };
+  await write(day(0), ['Standup: Umzug liegt im Plan #homelab', 'Nachmittags Backup-Test mit restic', 'Idee: Wochenrückblick als Vorlage anlegen']);
+  for (const offset of [2, 5]) {
+    await page.getByTitle(new RegExp(new Date(today.getFullYear(), today.getMonth(), today.getDate() - offset).toLocaleDateString('de-DE', { day: 'numeric', month: 'long' }))).first().click().catch(() => {});
+    await sleep(1200);
+    await write(day(offset), offset === 2 ? ['Rasen gemäht, Hecke wartet noch #garten'] : ['Erste Gedanken zur Hausrenovierung #renovierung', 'Angebote einholen bis Monatsende']);
+  }
+  await page.getByRole('button', { name: 'Heute' }).click().catch(() => {});
+  await page.mouse.click(1000, 860);
+  await sleep(2500);
+  await shot(page, 'journal_desktop.png');
+  await page.getByRole('button', { name: 'Journal', exact: true }).click(); // close it again
+
   await tab(page, 'Listen');
   await page.getByText('Wocheneinkauf', { exact: true }).first().click().catch(() => {});
   await shot(page, 'Listen_desktop.png');
@@ -75,6 +182,12 @@ const main = async () => {
   await mobile.getByText('Später im Browser weiter nutzen').click({ timeout: 5000 }).catch(() => {}); // install prompt
   await shot(mobile, 'Mobile_Triage.png');
 
+  await tab(mobile, 'Workspace');
+  await sleep(600);
+  await mobile.getByText(/^Homelab 2\.0/).first().click();
+  await sleep(1500);
+  await shot(mobile, 'Mobile_Workspace.png');
+
   await browser.close();
 };