Two multi-project bugs fixed:
1. validate_commit_msg.py: Hardcoded "DEVX-N" prefix → now uses
TASK_PREFIX from config.py (configurable via DEVX_TASK_PREFIX
env var, default: DEVX). Consumer projects like GRM set
DEVX_TASK_PREFIX=GRM, so the validator enforces "GRM-N:" prefix.
2. sync_wiki.py: DOCS_DIR was relative to __file__ (package
installation path) → now uses DEVX_DOCS_DIR env var or defaults
to ./docs (relative to CWD = repo root). Previously resolved to
.venv/lib/python3.12/docs/ which doesn't exist.
Added 3 tests for custom prefix validation (GRM prefix scenario).
Updated translations.json with new {prefix} parameter.
Generated with [Devin](https://devin.ai)
Co-Authored-By: Devin <158243242+devin-ai-integration[bot]@users.noreply.github.com>