docs(ci): add resolution-too-deep troubleshooting

Author: Sakeeb91

docs/CI_TROUBLESHOOTING.md

@@ -0,0 +1,15 @@
+# CI Troubleshooting
+
+## pip "resolution-too-deep"
+- Cause: overly broad/unconstrained dependencies force exhaustive resolution.
+- Fix: install with constraints to bound dependency space.
+  ```bash
+  pip install -r requirements.txt -c constraints.txt
+  ```
+- Ensure critical deps (e.g., `cryptography>=39.0.0`) have minimum versions.
+
+## General Tips
+- Re-run with `pip --verbose` to inspect resolution decisions.
+- Clear pip cache if resolution seems stuck: `pip cache purge`.
+- Keep `constraints.txt` in sync with `requirements.txt` when updating dependencies.
+