chore(scripts): make pre_commit_fable_mcp.sh location-independent

Derive REPO_ROOT from the script's own location instead of hardcoding
the absolute project path, so the hook keeps working if the project
directory is renamed or moved.

Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>

scripts/pre_commit_fable_mcp.sh

@@ -8,7 +8,7 @@
 
 set -euo pipefail
 
-REPO_ROOT="/home/bvandeusen/Nextcloud/Projects/fabledassistant"
+REPO_ROOT="$(cd "$(dirname "${BASH_SOURCE[0]}")/.." && pwd)"
 
 input=$(cat)
 command=$(echo "$input" | python3 -c "