fix: petr-import-source-events entry point points to correct module

- pyproject.toml: change entrypoint from official_event_import:main to source_mention_extract:main

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

Author: Pigbibi

pyproject.toml

@@ -18,7 +18,7 @@ test = ["pytest>=8"]
 petr-build-tracker = "political_event_tracking_research.tracker:main"
 petr-event-study = "political_event_tracking_research.event_study:main"
 petr-import-official-events = "political_event_tracking_research.official_event_import:main"
-petr-import-source-events = "political_event_tracking_research.official_event_import:main"
+petr-import-source-events = "political_event_tracking_research.source_mention_extract:main"
 petr-extract-source-mentions = "political_event_tracking_research.source_mention_extract:main"
 petr-fetch-rss-sources = "political_event_tracking_research.rss_source_fetch:main"