feat(git-hooks): implement conditional Husky activation system

- Implements conditional activation logic in husky.sh helper script
- Updates pre-commit hook to run linting only when enabled
- Updates commit-msg hook to validate messages only when enabled
- Adds .husky-enabled to .gitignore for user-specific activation
- Creates user activation instructions in .husky/README.md
- Provides graceful fallback when hooks are disabled

Activation: Environment variable, local file, or global config
Hooks: Pre-commit (linting) and commit-msg (validation)
Behavior: Optional activation with helpful instructions when disabled

.husky/commit-msg

@@ -1,10 +1,11 @@
-#!/usr/bin/env bash
-#
-# Husky Commit Message Hook
-# Validates commit message format using commitlint
-#
+#!/usr/bin/env sh
 . "$(dirname -- "$0")/_/husky.sh"
 
-# Run commitlint but don't fail the commit (|| true)
-# This provides helpful feedback without blocking commits
-npx commitlint --edit "$1" || true
+# Only run if Husky is enabled
+if [ "$HUSKY_ENABLED" = "1" ] || [ -f .husky-enabled ]; then
+  echo "Running commit-msg hooks..."
+  npx commitlint --edit "$1"
+else
+  echo "Husky commit-msg hook skipped (not enabled)"
+  exit 0
+fi