release: v1.5.4

1.5.3 shipped at 19:22, before the DM fix, the directions UI rework and the
newsletter reader fix. Bump to 1.5.4 so those can actually reach people.

- package.json 1.5.4 (-> versionName 1.5.4 / versionCode 10504).
- release-notes.txt: new v1.5.4 section (DM persistence + parallel send/read,
  bigger-map/app-like directions, underscore italics in the issue reader);
  trimmed v1.5.3 back to what was actually published.

package.json

@@ -1,7 +1,7 @@
 {
   "name": "skate-spots",
   "private": true,
-  "version": "1.5.3",
+  "version": "1.5.4",
   "type": "module",
   "homepage": "https://skate-spots.com",
   "scripts": {

release-notes.txt

@@ -1,6 +1,6 @@
-v1.5.3
+v1.5.4
 
-✉️ Direct messages fixed
+✉️ Direct messages actually arrive now
 - Your DM inbox relays were being forgotten every time the app loaded, so
   messages were sent to your normal relays instead of the ones the other person
   actually reads — which is why DMs looked like they never arrived. Your DM
@@ -8,10 +8,20 @@ v1.5.3
 - Sending and loading DMs no longer stall or break because of one dead or
   login-only relay in your list; they now run in parallel.
 
+🧭 Directions look and feel like a navigation screen
+- A much bigger map, with a metric scale bar, and the plan at a glance:
+  distance, time, arrival, step count and the average speed the route assumes.
+- The map stays put while the details scroll, and Start/Stop is pinned at the
+  bottom where your thumb already is.
+
+📰 Newsletter reader
+- Issue intros render as proper italics instead of showing literal underscores.
+
+---
+
+v1.5.3
+
 🧭 Real navigation, not just a route preview
-- A much bigger map (with a metric scale bar), and the plan now reads at a
-  glance: distance, time and arrival time as clear stats, plus step count and
-  the average speed the route assumes. Start/Stop stays pinned at the bottom.
 - Travel modes finally give genuinely different answers: walking 13 min, biking
   5, driving 2 on the same trip. Before, every mode showed the same number.
 - Route steps — the actual turns and street names. Tap a step to jump to it on