Install the dev extra CI's lint and test steps need

ruff and pytest are declared under [project.optional-dependencies].dev, which
`uv run` does not install by default, so both steps died with
"Failed to spawn: ruff" before running anything. The lockfile check had been
masking this by failing first.

Pass --extra dev to both. Reproduced the spawn failure locally with
`uv run --no-dev` and confirmed the fixed commands report 253 passing tests and
a clean ruff run.

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>

Author: mnm-matin

.github/workflows/ci.yml

@@ -34,11 +34,13 @@ jobs:
       - name: Check lockfile
         run: uv lock --check
 
+      # ruff and pytest are declared in the `dev` extra, which uv does not
+      # install by default; without it both steps fail to spawn their tool.
       - name: Lint
-        run: uv run ruff check src tests examples
+        run: uv run --extra dev ruff check src tests examples
 
       - name: Test
-        run: uv run pytest -q
+        run: uv run --extra dev pytest -q
 
   frontend:
     name: Frontend