test: add API integration suite, fixtures, and frontend unit tests

Author: clean6378-max-it

.github/workflows/ci.yml

@@ -68,10 +68,14 @@ jobs:
 
   mypy:
     runs-on: ubuntu-latest
+    permissions:
+      contents: read
     steps:
-      - uses: actions/checkout@v4
+      - uses: actions/checkout@34e114876b0b11c390a56381ad16ebd13914f8d5 # v4
+        with:
+          persist-credentials: false
 
-      - uses: actions/setup-python@v5
+      - uses: actions/setup-python@a26af69be951a213d495a4c3e4e4022e16d87065 # v5
         with:
           python-version: "3.12"
           cache: pip