feat: sync with upstream — v1.2.0, in-app updates, Projects, modules

Brings the public tree back in line with the development repo after several
weeks of drift caused by a stale publish include list.

New:
- In-app update path: GET /update/check compares the checkout against
  origin/main and POST /update/apply runs `ncp upgrade` detached (pull,
  rebuild, restart). The sidebar shows the version, checks on click, and
  offers an "update available" pill.
- Projects: a project workspace groups chats and RAG documents, with
  per-project instructions and document retrieval scoped to the active
  project. Replaces the standalone Documents page.
- modules/: auto-discovered feature plugins (mail, network) with their
  frontend counterparts and tests.
- Memory curation runs in-process (synapse/memory/curator.py) on the chat
  model when a conversation goes idle. The separate memory service on :8001
  is gone, along with the launcher lines that started it.

Also: the KDE theme, panel and Promethean terminal assets, the full test
suite, and VERSION 1.2.0.

🤖 Generated with [Claude Code](https://claude.com/claude-code)

bin/panel/nexus-applet.sh

@@ -15,15 +15,13 @@ port_up() {
 state() { port_up "$1" && echo "up" || echo "down"; }
 
 BACKEND=$(state 8000)   # Synapse
-MEMORY=$(state 8001)    # Memory service
 FRONTEND=$(state 5173)  # Vite frontend
 
 up=0
 [ "$BACKEND"  = up ] && up=$((up + 1))
-[ "$MEMORY"   = up ] && up=$((up + 1))
 [ "$FRONTEND" = up ] && up=$((up + 1))
 
-if   [ "$up" -eq 3 ]; then ICON="$ICON_DIR/nexus-on.png"
+if   [ "$up" -eq 2 ]; then ICON="$ICON_DIR/nexus-on.png"
 elif [ "$up" -eq 0 ]; then ICON="$ICON_DIR/nexus-off.png"
 else                       ICON="$ICON_DIR/nexus-partial.png"
 fi
@@ -31,8 +29,7 @@ fi
 dot() { [ "$1" = up ] && echo "●" || echo "○"; }
 
 echo "<img>$ICON</img>"
-echo "<tool>NexusOS  —  ${up}/3 services up
+echo "<tool>NexusOS  —  ${up}/2 services up
 $(dot "$BACKEND")  Synapse backend   :8000
-$(dot "$MEMORY")  Memory service      :8001
 $(dot "$FRONTEND")  Frontend (Vite)       :5173</tool>"
 echo "<click>$HOME/.local/bin/nexus-popup.py</click>"