fix(claude): allow reading and editing .env*.example files

[p-chan]

Why

The deny rules Read(!.env*.example) and Edit(!.env*.example) were meant to exempt example files from Read(.env*) and Edit(.env*), but permission rules have no negation. Each rule is matched independently, so .env.example was denied as well.

What

• Add home/.claude/hooks/personal-block-env.sh, a PreToolUse hook that denies .env* files except .env*.example
  • Match file names case-insensitively for case-insensitive file systems
  • Block the tool call with exit code 2 when the check fails
• Run the hook for Read, Edit, Write, MultiEdit, and NotebookEdit
• Replace the .env* deny rules in home/.claude/settings.json with Read deny rules for common names (.env, .env.local, .env.*.local, .env.development, .env.production), because @ mentions do not trigger PreToolUse hooks

Notes

• Unlike Read deny rules, the hook does not cover the Grep and Glob tools. This will be handled separately
• The hook checks the given file name and does not resolve symlinks