refactor(songs): rename render.py to publish.py

render.py was a misleading name — the script validates, renders,
and writes to MediaWiki (and will soon upload LRC files too).
publish.py better describes the full scope of the entry point.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

.gitea/workflows/publish-songs.yml

@@ -74,7 +74,7 @@ jobs:
         run: |
           MODE="${{ steps.diff.outputs.mode }}"
           if [ "$MODE" = "all" ] || [ "${{ inputs.FULL_PUBLISH }}" = "true" ]; then
-            python auto-wiki/pipelines/songs/render.py \
+            python auto-wiki/pipelines/songs/publish.py \
               --source-dir ncmr-songs \
               --all
           else
@@ -84,7 +84,7 @@ jobs:
               exit 0
             fi
             # shellcheck disable=SC2086
-            python auto-wiki/pipelines/songs/render.py \
+            python auto-wiki/pipelines/songs/publish.py \
               --source-dir ncmr-songs \
               --files $FILES
           fi