feat: add live config profile refresh

- Standardize built-in tool users for shared writable profile mounts
- Mount canonical non-Git profile sources across compatible instances
- Report restart-required outcomes and guard active profile deletion
- Surface restart feedback in config profile editing

Quality gates: frontend build passed; backend py_compile and LSP passed.
Skipped: backend pytest/Ruff unavailable; Docker/manual checks not approved.

tool-images/code-server.dockerfile

@@ -22,7 +22,11 @@ RUN curl -fsSL https://deb.nodesource.com/setup_20.x | bash - \
 # Set up git
 RUN git config --global init.defaultBranch main
 
-# Code-server runs as abc user by default
+# The LinuxServer entrypoint maps abc to this shared UID/GID before starting
+# code-server, so writable Config Profile mounts are compatible with other
+# built-in tool containers.
+ENV PUID=1000 \
+    PGID=1000
 USER abc
 
 EXPOSE 8443