[BUG] nix build flake url not correctly parsed for permissions allow

Environment

• Platform (select one):
• [X] Anthropic API
• [ ] AWS Bedrock
• [ ] Google Vertex AI
• [ ] Other: <!-- specify -->
• Claude CLI version: 1.0.51<!-- output of claude --version -->
• Operating System: nixos unstable<!-- e.g. macOS 14.3, Windows 11, Ubuntu 22.04 -->
• Terminal: urxvtc <!-- e.g. iTerm2, Terminal App -->

Bug Description

When adding "nix build:" to the allow list because of the flake uri syntax ".#abc" its is not included in "nix build: "
<!-- A clear and concise description of the bug -->

Steps to Reproduce

1. download any flake using git clone<!-- First step -->
2. add Bash(nix build:*) to settings.local.json .permissions.allow[]
3. attempt to build path in flake nix build .#abc <!-- Second step -->
4. get permission requirement<!-- And so on... -->

Expected Behavior

claude code gets to build in the nix sandbox without permission check
<!-- What you expected to happen -->

Actual Behavior

gets permission check
<!-- What actually happened -->

Additional Context

N.A.
<!-- Add any other context about the problem here, such as screenshots, logs, etc. -->