feat(sync): re-auth prompt on expired session + server deployment artifacts

On auth failure during pull (access + refresh both expired), sync_plugin now
fires SyncConfigureRequestEvent so the Connect modal reopens automatically
instead of leaving the player with a silent error status. The modal's existing
double-open guard keeps repeated failures idempotent.

Also removes the unused SyncAuthResultEvent (results handled inline in
SyncSetupPlugin via PendingAuthTask polling) and adds server deployment
artifacts: Dockerfile (multi-stage, SQLX_OFFLINE), docker-compose.yml (SQLite
volume, health-check), and .env.example for local development setup.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

solitaire_server/.env.example

@@ -0,0 +1,13 @@
+# Copy this file to .env and fill in the values.
+# The server reads these on startup via dotenvy.
+
+# SQLite database path. For local dev use a file path; for Docker use the
+# volume-mounted path (see docker-compose.yml).
+DATABASE_URL=sqlite://sol.db
+
+# HS256 signing secret for JWT tokens. Use at least 32 random characters.
+# Generate one with: openssl rand -hex 32
+JWT_SECRET=change-me-use-openssl-rand-hex-32
+
+# TCP port to listen on (optional, default 8080).
+# SERVER_PORT=8080