Update backend dependency versions

Bump several backend dependencies to newer releases and sync requirement files. Notable changes: flask, python-dotenv, pillow, cairosvg, cryptography, fastapi, and requests were updated; lxml and starlette entries were added/updated in build.json; requirements.txt lxml pinned to 6.1.1. Also update the build.json last_build timestamp.

Author: Nrwx

backend/build.json

@@ -14,7 +14,7 @@
     "project_name": "unity-texture-generator"
   },
   "dependencies": {
-    "last_build": "2026-06-22T18:03:19.767190Z",
+    "last_build": "2026-06-24T11:46:50.715358Z",
     "config": {
       "library_policy": {
         "auto_update": true,
@@ -35,11 +35,11 @@
     },
     "libraries": {
       "flask": {
-        "version": "3.0.3",
+        "version": "3.1.3",
         "freeze": false
       },
       "python-dotenv": {
-        "version": "1.1.1",
+        "version": "1.2.2",
         "freeze": false
       },
       "diffusers": {
@@ -58,12 +58,16 @@
         "version": "0.8.0rc0",
         "freeze": false
       },
+      "lxml": {
+        "version": "6.1.1",
+        "freeze": false
+      },
       "pillow": {
-        "version": "11.3.0",
+        "version": "12.2.0",
         "freeze": false
       },
       "cairosvg": {
-        "version": "2.8.2",
+        "version": "2.9.0",
         "freeze": false
       },
       "fonttools": {
@@ -75,15 +79,19 @@
         "freeze": false
       },
       "cryptography": {
-        "version": "46.0.3",
+        "version": "48.0.1",
         "freeze": false
       },
       "dpnp": {
         "version": "0.18.1",
         "freeze": false
       },
       "fastapi": {
-        "version": "0.115.0",
+        "version": "0.138.0",
+        "freeze": false
+      },
+      "starlette": {
+        "version": "1.3.1",
         "freeze": false
       },
       "flask-cors": {
@@ -127,7 +135,7 @@
         "freeze": false
       },
       "requests": {
-        "version": "2.32.5",
+        "version": "2.33.0",
         "freeze": false
       },
       "scipy": {

backend/requirements.txt

@@ -32,7 +32,7 @@ Jinja2==3.1.4
 jiter==0.10.0
 jsonpointer==2.1
 keyring==25.7.0
-lxml==5.3.0
+lxml==6.1.1
 matplotlib==3.10.0
 mkl==2025.3.0
 mkl-service==2.4.0