fix: ensure VENV_DIR is absolute path in local install (#96)

When installing from within the git repository, VENV_DIR remained as
the relative path "venv", which caused wrapper scripts in ~/.local/bin/
to fail when executed from any directory other than the repo root.

This broke launching from app drawers/desktop entries since they don't
set the working directory to the repo location.

Fix: Convert VENV_DIR to an absolute path ($INSTALL_DIR/$VENV_DIR) when
running from local repository, ensuring wrapper scripts work regardless
of current working directory.

install.sh

@@ -123,6 +123,8 @@ if [ -f "setup.py" ] || [ -f "pyproject.toml" ]; then
     # Running from within the repo
     INSTALL_DIR="$(pwd)"
     print_info "Running from local repository: $INSTALL_DIR"
+    # Convert VENV_DIR to absolute path for wrapper scripts
+    VENV_DIR="$INSTALL_DIR/$VENV_DIR"
 else
     # Running remotely (e.g., via curl | bash)
     print_info "Installing Vocalinux version: ${INSTALL_TAG}"