Sensitive path blocklist now case-insensitive

What's Changed

• fix(security): enforce case-insensitive sensitive path blocklist and vscode hitl by @luisfelipe-alt in https://github.com/google-gemini/gemini-cli/pull/27966

Full Changelog: https://github.com/google-gemini/gemini-cli/compare/v0.51.0-nightly.20260626.gb14416447...v0.51.0-nightly.20260628.gae0a3aa7b