chore: bump version to 0.9.4, backfill changelog with real commit times

Every entry got a time component pulled from actual git commit
timestamps (git log --date=format), not guessed — precise enough to
disambiguate the many same-day releases from this session. 0.2.0 and
0.1.0 kept date-only/"earlier" since no reliable timestamp exists for
them. Also adds the 0.9.4 entry for the previous action-buttons/
view-toggle mobile fix, which shipped without its own version bump.

package.json

@@ -1,6 +1,6 @@
 {
   "name": "epicure",
-  "version": "0.9.3",
+  "version": "0.9.4",
   "private": true,
   "scripts": {
     "dev": "pnpm --filter web dev",