entrypoint: alias ~/.coderai to the mounted config dir (fix HOME-based lookups)

Trained LoRAs, characters, environments and voices are resolved from the legacy
HOME-based dir ~/.coderai, not from --config. In the container the user's home
(e.g. /home/ubuntu) isn't where config is mounted ($CONFIG_DIR/coderai), so those
lookups missed the mounted data and image-gen failed with "LoRA '<name>' not found
on server". Symlink ~/.coderai -> $CODERAI_CONFIG_DIR/coderai so HOME-based and
--config lookups agree, removing the need for an extra per-deployment --map. Acts
only when safe (a symlink, missing, or an empty dir) so a user-mounted volume or
real data is never clobbered.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01RdMufYvtTbtGDWsiZVoXce