feat: add justified layout modes and aspect-ratio-aware mosaic (#146)

- Add Flickr justified-layout and react-photo-album as masonry mode options
- Implement aspect-ratio-aware mosaic layout that dynamically selects
  patterns based on photo orientations to minimize cropping
- Add 9 mosaic pattern types optimized for different orientation combinations
- Add theme customizer options for masonry mode selection (columns/rows/flickr/justified)
- Add i18n translations for new layout options

frontend/package-lock.json

@@ -27,6 +27,7 @@
         "i18next": "^25.3.1",
         "i18next-browser-languagedetector": "^8.2.0",
         "i18next-http-backend": "^3.0.2",
+        "justified-layout": "^4.1.0",
         "linkifyjs": "^4.3.2",
         "lodash": "^4.17.21",
         "lowlight": "^2.9.0",
@@ -38,6 +39,7 @@
         "react-i18next": "^15.6.0",
         "react-image-gallery": "^1.2.11",
         "react-intersection-observer": "^9.4.3",
+        "react-photo-album": "^3.4.0",
         "react-router-dom": "^6.8.0",
         "react-toastify": "11.0.5",
         "tailwind-merge": "^3.3.1"
@@ -4664,6 +4666,12 @@
         "node": ">=6"
       }
     },
+    "node_modules/justified-layout": {
+      "version": "4.1.0",
+      "resolved": "https://registry.npmjs.org/justified-layout/-/justified-layout-4.1.0.tgz",
+      "integrity": "sha512-M5FimNMXgiOYerVRGsXZ2YK9YNCaTtwtYp7Hb2308U1Q9TXXHx5G0p08mcVR5O53qf8bWY4NJcPBxE6zuayXSg==",
+      "license": "ISC"
+    },
     "node_modules/keyv": {
       "version": "4.5.4",
       "resolved": "https://registry.npmjs.org/keyv/-/keyv-4.5.4.tgz",
@@ -5813,6 +5821,27 @@
       "integrity": "sha512-24e6ynE2H+OKt4kqsOvNd8kBpV65zoxbA4BVsEOB3ARVWQki/DHzaUoC5KuON/BiccDaCCTZBuOcfZs70kR8bQ==",
       "license": "MIT"
     },
+    "node_modules/react-photo-album": {
+      "version": "3.4.0",
+      "resolved": "https://registry.npmjs.org/react-photo-album/-/react-photo-album-3.4.0.tgz",
+      "integrity": "sha512-pPaCoxEfVDhowpqxECq4SOD5kzP1Uao8PEN11Jasxayv4cZjad3Fy8SlKt6wvtLnVJRtOjsQDU/ZnnUuberwMg==",
+      "license": "MIT",
+      "engines": {
+        "node": ">=18"
+      },
+      "funding": {
+        "url": "https://github.com/sponsors/igordanchenko"
+      },
+      "peerDependencies": {
+        "@types/react": "^18 || ^19",
+        "react": "^18 || ^19"
+      },
+      "peerDependenciesMeta": {
+        "@types/react": {
+          "optional": true
+        }
+      }
+    },
     "node_modules/react-refresh": {
       "version": "0.17.0",
       "resolved": "https://registry.npmjs.org/react-refresh/-/react-refresh-0.17.0.tgz",