Repair OpenRouter image, video and audio integration

Preserve existing workflows while adding capability-based catalogs, dedicated
image requests, resumable native video, validated audio and explicit chat tiers.
Cover compatibility, billing-sensitive retries, credentials and cancellation.

Co-authored-by: Arthur Reboul Salze <22814805+ArthurReboulSalze@users.noreply.github.com>
Co-authored-by: Dookie <me@djdookie.de>

.github/workflows/tests.yml

@@ -0,0 +1,22 @@
+name: Tests
+on:
+  push:
+  pull_request:
+permissions:
+  contents: read
+jobs:
+  regression:
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v4
+      - uses: actions/setup-python@v5
+        with:
+          python-version: '3.11'
+      - uses: actions/setup-node@v4
+        with:
+          node-version: '22'
+      - run: pip install requests numpy Pillow tiktoken
+      - run: pip install torch --index-url https://download.pytorch.org/whl/cpu
+      - run: python -m unittest discover -s tests -t .
+      - run: node tests/test_frontend_controls.mjs
+      - run: git diff --check