fix(ui): message bubble color, received-message hop count, list wrap-around, age fallback; add sim WASM build workflow

- Unselected message bubbles no longer carry a stray light-filled header
  strip behind the sender name -- the one place with a filled patch on an
  otherwise plain row. Selected fill is unchanged.
- Received DMs and channel posts now show their hop count as the same tiny
  digit icon a sent message already uses for its repeater/echo count, using
  the hop path the mesh already records for incoming messages.
- DM/channel history list: UP at the oldest message now wraps straight to
  the newest (not the compose row), closing the loop the same way every
  other list in the UI does at its ends.
- A received message's age no longer goes blank when its timestamp reads
  slightly ahead of the device's own clock (sender/receiver skew, or an
  unsynced receiver) or is genuinely unknown -- both now show the receipt
  time instead of leaving the row with just a name and hop count.
- release-notes.md: add the v1.28 section covering the above plus this
  cycle's already-committed dev fixes (GPS altitude field, units
  compliance, noise floor, Msg wake location, bot relay tracking, PR #34).
- Add .github/workflows/build-solo-sim.yml: builds the companion+repeater
  WASM sim via Emscripten and attaches it as a fixed-name asset to the tag's
  draft release, independent of the hardware firmware build job.

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>

.github/workflows/build-solo-sim.yml

@@ -0,0 +1,67 @@
+name: Build Solo Sim (WASM)
+
+# Builds the companion_radio browser sim (real firmware compiled to WASM via
+# Emscripten, see variants/sim/) and attaches it to the same draft release
+# build-solo-firmwares.yml creates for this tag, as a single fixed-name
+# asset: solo-sim-wasm.zip. Fixed name (no version in it) so
+# meshcore-solo-site's server-side deploy script can always fetch it from
+# the stable "latest release" download URL without knowing the tag --
+# see meshcore-solo-site/scripts/fetch-wasm-release.sh.
+#
+# Independent job/workflow from the hardware firmware builds: different
+# toolchain (Emscripten, not PlatformIO), and a WASM build failure shouldn't
+# block or delay the actual firmware release.
+
+permissions:
+  contents: write
+
+on:
+  workflow_dispatch:
+  push:
+    tags:
+      - 'v*'
+
+jobs:
+  build-sim-wasm:
+    runs-on: ubuntu-latest
+    steps:
+      - name: Clone Repo
+        uses: actions/checkout@v4
+
+      - name: Cache emsdk
+        uses: actions/cache@v4
+        with:
+          path: variants/sim/tools/emsdk
+          key: emsdk-6.0.9-${{ runner.os }}
+
+      - name: Install emsdk 6.0.9
+        run: |
+          if [ ! -x variants/sim/tools/emsdk/upstream/emscripten/em++ ]; then
+            rm -rf variants/sim/tools/emsdk
+            git clone --depth 1 https://github.com/emscripten-core/emsdk.git variants/sim/tools/emsdk
+            cd variants/sim/tools/emsdk
+            python3 ./emsdk.py install 6.0.9
+            python3 ./emsdk.py activate 6.0.9
+          else
+            echo "emsdk 6.0.9 already cached"
+          fi
+
+      - name: Build companion WASM
+        run: variants/sim/build_wasm.sh
+
+      - name: Build repeater WASM
+        run: variants/sim/build_wasm_repeater.sh
+
+      - name: Package
+        run: |
+          mkdir -p out/wasm/companion out/wasm/repeater
+          cp variants/sim/web/build/meshcore_sim.js variants/sim/web/build/meshcore_sim.wasm out/wasm/companion/
+          cp variants/sim/web/build/repeater/meshcore_sim_repeater.js variants/sim/web/build/repeater/meshcore_sim_repeater.wasm out/wasm/repeater/
+          cd out && zip -r solo-sim-wasm.zip wasm
+
+      - name: Attach to release
+        if: startsWith(github.ref, 'refs/tags/')
+        uses: softprops/action-gh-release@v2
+        with:
+          draft: true
+          files: out/solo-sim-wasm.zip