fix: Resolve Docker volume permissions for SQLite database

Fixed SQLITE_READONLY errors by implementing proper volume permission
handling in Docker container. The issue occurred because Docker volumes
are mounted with root ownership, preventing the non-root nuxt user from
writing to the database.

Solution:
- Added docker-entrypoint.sh script to handle permission fixes
- Container starts as root to fix /app/data permissions
- Uses su-exec to drop privileges to nuxt user after fixing permissions
- Maintains security by running application as non-root user

This allows the SQLite database to be properly created and modified
while keeping the container secure with non-root execution.

Fixes:
- "attempt to write a readonly database" errors
- Session cleanup failures
- Rate limit cleanup failures
- Password reset cleanup failures
- Admin credential generation on first launch

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

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

docker-entrypoint.sh

@@ -0,0 +1,17 @@
+#!/bin/sh
+set -e
+
+# Ensure data directory exists and has correct permissions
+# This is needed because Docker volumes may be mounted with root ownership
+if [ ! -d /app/data ]; then
+  mkdir -p /app/data
+fi
+
+# If running as root, fix permissions and switch to nuxt user
+if [ "$(id -u)" = "0" ]; then
+  chown -R nuxt:nodejs /app/data
+  exec su-exec nuxt "$@"
+else
+  # Already running as nuxt user
+  exec "$@"
+fi