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)

assets/themes/restore-snapshot/xfconf-xml/xsettings.xml

@@ -1,4 +1,4 @@
-<?xml version="1.1" encoding="UTF-8"?>
+<?xml version="1.0" encoding="UTF-8"?>
 
 <channel name="xsettings" version="1.0">
   <property name="Net" type="empty">
@@ -27,6 +27,8 @@
     <property name="MonospaceFontName" type="empty"/>
     <property name="IconSizes" type="empty"/>
     <property name="KeyThemeName" type="empty"/>
+    <property name="ToolbarStyle" type="empty"/>
+    <property name="ToolbarIconSize" type="empty"/>
     <property name="MenuImages" type="bool" value="false"/>
     <property name="ButtonImages" type="empty"/>
     <property name="MenuBarAccel" type="empty"/>
@@ -35,8 +37,6 @@
     <property name="DecorationLayout" type="string" value="icon,menu:minimize,maximize,close"/>
     <property name="DialogsUseHeader" type="empty"/>
     <property name="TitlebarMiddleClick" type="empty"/>
-    <property name="ToolbarStyle" type="empty"/>
-    <property name="ToolbarIconSize" type="empty"/>
     <property name="IMPreeditStyle" type="empty"/>
     <property name="IMStatusStyle" type="empty"/>
     <property name="IMModule" type="empty"/>