chore: add .mypy_cache and .venv to gitignore

.gitignore

@@ -1,16 +1,20 @@
-# instructions for agents
-.github/instructions/
-.agents
-skills-lock.json
-
-# environment variables
-.env
-
-# python cache
-__pycache__/
-
-# app runtime data (feeds, caches, scan state - regenerated each run)
-app/data/
-
-# generated reports
-app/reports/
+# instructions for agents
+.github/instructions/
+.agents
+skills-lock.json
+
+# environment variables
+.env
+
+# python cache
+__pycache__/
+.mypy_cache/
+
+# python virtual environment
+.venv/
+
+# app runtime data (feeds, caches, scan state - regenerated each run)
+app/data/
+
+# generated reports
+app/reports/