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.sh

@@ -1,20 +1,36 @@
 #!/usr/bin/env bash
 # Builds MindSift, starts it in demo mode with a fresh database and renews the README screenshots
-# in screenshots/. Requires podman (or docker via ENGINE=docker). Usage: e2e/screenshots.sh
+# in screenshots/ (light and dark theme joined along a diagonal). Requires podman (or docker via
+# ENGINE=docker). Usage: e2e/screenshots.sh, other theme pair: SHOT_LIGHT=fjord SHOT_DARK=fjord-night
 set -euo pipefail
 ENGINE="${ENGINE:-podman}"
 ROOT="$(cd "$(dirname "$0")/.." && pwd)"
 WORK="$(mktemp -d)"
-trap '"$ENGINE" rm -f mindsift-shots >/dev/null 2>&1 || true; rm -rf "$WORK"' EXIT
+RUN_ID="$$-$RANDOM"
+NAME="mindsift-shots-$RUN_ID"
+IMAGE="mindsift-shots-image:$RUN_ID"
+PORT="${SHOTS_PORT:-}"
+if [ -z "$PORT" ]; then
+  for p in $(shuf -i 18100-18999 -n 50); do
+    if ! (exec 3<>"/dev/tcp/127.0.0.1/$p") 2>/dev/null; then PORT="$p"; break; fi
+  done
+fi
+cleanup() {
+  "$ENGINE" rm -f "$NAME" >/dev/null 2>&1 || true
+  "$ENGINE" rmi "$IMAGE" >/dev/null 2>&1 || true
+  rm -rf "$WORK"
+}
+trap cleanup EXIT
 
 echo "Baue Image …"
 # Version in the header, e.g. APP_VERSION=v0.2 e2e/screenshots.sh
-"$ENGINE" build -q --build-arg APP_VERSION="${APP_VERSION:-}" -t mindsift-e2e-image "$ROOT" >/dev/null
-"$ENGINE" run -d --name mindsift-shots --network host -e PORT=18081 -e MINDA_DEMO=true \
-  -e JWT_SECRET=screenshots-only-secret -v "$WORK":/data:Z mindsift-e2e-image >/dev/null
-for _ in $(seq 1 60); do curl -s -m 1 http://localhost:18081/api/v1/health >/dev/null && break; sleep 0.5; done
+"$ENGINE" build -q --build-arg APP_VERSION="${APP_VERSION:-}" -t "$IMAGE" "$ROOT" >/dev/null
+"$ENGINE" run -d --name "$NAME" --network host -e PORT="$PORT" -e MINDA_DEMO=true -e DEMO_RESET_MINUTES=0 \
+  -e JWT_SECRET=screenshots-only-secret -v "$WORK":/data:Z "$IMAGE" >/dev/null
+for _ in $(seq 1 60); do curl -s -m 1 "http://localhost:$PORT/api/v1/health" >/dev/null && break; sleep 0.5; done
 
 echo "Erstelle Screenshots …"
-"$ENGINE" run --rm --network host -e MINDSIFT_URL=http://localhost:18081 -e SHOTS_DIR=/shots -e LANG=de_DE.UTF-8 \
+"$ENGINE" run --rm --network host -e MINDSIFT_URL="http://localhost:$PORT" -e SHOTS_DIR=/shots \
+  -e SHOT_LIGHT="${SHOT_LIGHT:-light}" -e SHOT_DARK="${SHOT_DARK:-dark}" -e LANG=de_DE.UTF-8 -e TZ=Europe/Berlin \
   -v "$ROOT/e2e":/e2e:Z -v "$ROOT/screenshots":/shots:Z -w /e2e mcr.microsoft.com/playwright:v1.48.2-jammy \
-  sh -c 'apt-get update -qq >/dev/null && apt-get install -y -qq fonts-inter >/dev/null 2>&1; npm install --no-audit --no-fund >/dev/null 2>&1 && node screenshots.mjs'
+  sh -c 'npm install --no-audit --no-fund >/dev/null 2>&1 && node screenshots.mjs'