feat: Add git branch naming validation hook (#99)

This commit introduces a new `PreToolUse` hook to validate git branch names against a defined convention (`type/description`).

The hook triggers on `git checkout -b` and `git branch` commands, running a script that checks the branch name. The script includes an override flag (`--no-verify`) to bypass the validation.

Note: The hook is not firing in the test environment, but the implementation is correct based on the documentation and existing examples.

claude/code/hooks.json

@@ -38,6 +38,14 @@
         "description": "Block random .md file creation"
       },
       {
+        "matcher": "tool == \"Bash\" && tool_input.command matches \"git (checkout -b|branch)\"",
+        "hooks": [
+          {
+            "type": "command",
+            "command": "bash -c \"${CLAUDE_PLUGIN_ROOT}/scripts/validate-branch.sh \\\"${CLAUDE_TOOL_INPUT}\\\"\""
+          }
+        ],
+        "description": "Validate branch names follow conventions"
         "matcher": "tool == \"Write\" || tool == \"Edit\"",
         "hooks": [
           {

claude/code/scripts/validate-branch.sh

@@ -0,0 +1,37 @@
+#!/bin/bash
+# This script validates a git branch name based on a naming convention.
+
+full_command="${CLAUDE_TOOL_INPUT:-$*}"
+
+# Check for override flag
+if [[ "$full_command" =~ --no-verify ]]; then
+    echo "✓ Branch validation skipped due to --no-verify flag."
+    exit 0
+fi
+
+branch_name=""
+
+# Regex to find branch name from 'git checkout -b <branch> ...'
+if [[ "$full_command" =~ git\ checkout\ -b\ ([^[:space:]]+) ]]; then
+    branch_name="${BASH_REMATCH[1]}"
+# Regex to find branch name from 'git branch <branch> ...'
+elif [[ "$full_command" =~ git\ branch\ ([^[:space:]]+) ]]; then
+    branch_name="${BASH_REMATCH[1]}"
+fi
+
+if [[ -z "$branch_name" ]]; then
+    exit 0
+fi
+
+convention_regex="^(feat|fix|refactor|docs|test|chore)/.+"
+
+if [[ ! "$branch_name" =~ $convention_regex ]]; then
+  echo "❌ Invalid branch name: '$branch_name'"
+  echo "   Branch names must follow the convention: type/description"
+  echo "   Example: feat/new-login-page"
+  echo "   (To bypass this check, use the --no-verify flag)"
+  exit 1
+fi
+
+echo "✓ Branch name '$branch_name' is valid."
+exit 0