Propagate Modern.js publicDir assets through sync + Docker build

The config/public/ directory (fonts, images, leaflet icons, favicons) is
Modern.js's publicDir convention — copied into dist/standalone/public/ at
build time. Two pre-existing gaps caused this to break on the deployed
SSR image and any fresh sync:

- scripts/sync-to-flights-front.sh did not copy config/ to the target
  repo, so the flights-front tree was missing /assets/** entirely.
- Dockerfile.react only copied src/, skipping config/; pnpm
  build:standalone ran without a publicDir source.

Result was that every /assets/** URL served the SSR HTML index with
Content-Type: text/html, producing OTS font-parse errors
(sfntVersion 1008821359 == '<!DT') and silently broken images.

Fix mirrors what was applied ad-hoc in Aeroflot.Flights.Front; this makes
future syncs and Docker builds carry the assets automatically.

scripts/sync-to-flights-front.sh

@@ -35,6 +35,10 @@ echo "2/5  Copying source files..."
 cp -r "$SRC_DIR/src"                    "$TARGET_DIR/src"
 cp -r "$SRC_DIR/tests"                  "$TARGET_DIR/tests"
 cp -r "$SRC_DIR/scripts"                "$TARGET_DIR/scripts"
+# Modern.js publicDir — fonts, images, leaflet icons, favicons. Copied to
+# dist/standalone/public/ at build time. Without these the app serves the
+# SPA index for /assets/** and breaks @font-face, img references, tile icons.
+cp -r "$SRC_DIR/config"                 "$TARGET_DIR/config"
 cp    "$SRC_DIR/package.json"           "$TARGET_DIR/package.json"
 cp    "$SRC_DIR/pnpm-lock.yaml"         "$TARGET_DIR/pnpm-lock.yaml"
 cp    "$SRC_DIR/tsconfig.json"          "$TARGET_DIR/tsconfig.json"
@@ -45,6 +49,7 @@ cp    "$SRC_DIR/playwright.config.ts"   "$TARGET_DIR/playwright.config.ts"
 cp    "$SRC_DIR/eslint.config.js"       "$TARGET_DIR/eslint.config.js"
 cp    "$SRC_DIR/Makefile"               "$TARGET_DIR/Makefile"
 cp    "$SRC_DIR/CLAUDE.md"              "$TARGET_DIR/CLAUDE.md"
+cp    "$SRC_DIR/AGENTS.md"              "$TARGET_DIR/AGENTS.md"
 
 # Dockerfile — use the SSR-specific one
 cp    "$SRC_DIR/Dockerfile.react"       "$TARGET_DIR/Dockerfile"