Add Django Admin action to run blog scraper

[Gurudevkini]

Summary

This pull request adds a Django Admin action to the existing Blog admin, allowing an administrator to trigger the workshop's existing scraper directly from the Admin UI.

The action calls start_extraction() from myworld/web_scrapper.py and displays a success or error message depending on the result.

Changes

• Added run_scraper as a Django Admin action in myworld/members/admin.py.
• Connected the action to the existing BlogAdmin using actions = [run_scraper].
• The action calls the existing start_extraction() function from web_scrapper.py.
• Added success feedback when the scraper completes successfully.
• Added error feedback when the scraper raises an exception.
• No changes were made to the models, migrations, Docker configuration, or scraper implementation.

Existing Workshop Functionality

The following functionality was already provided by the workshop:

• Django project with the members app.
• Students and Blog Django models.
• Django Admin registration for the models.
• PostgreSQL database integration.
• Docker Compose setup with Django and PostgreSQL services.
• Existing database migrations for the Blog and Students models.
• Python Insider scraper using Requests and BeautifulSoup.
• Existing scraper persistence using psycopg2 and SQL.

Data Flow

The new Admin action provides the following flow:

Django Admin
↓
run_scraper()
↓
start_extraction()
↓
web_scrapper.py
↓
Python Insider
↓
BeautifulSoup + Requests
↓
PostgreSQL

The existing scraper clears the members_blog table and inserts the scraped blog records using psycopg2.

Limitations

• The Admin action does not use the selected Blog queryset; it triggers a full scraper refresh.
• The scraper currently uses psycopg2 and raw SQL rather than Django ORM.
• The scraper establishes its PostgreSQL connection when web_scrapper is imported.
• The Admin action runs the scraper synchronously as part of the Admin request.
• The success message does not report the number of records inserted.
• There are currently no tests specifically covering the new Admin action.

Verification

• The current branch contains the Admin action in myworld/members/admin.py.
• The action is registered on BlogAdmin.
• The existing scraper remains unchanged.
• Django Admin and scraper behavior were manually verified during development.

Scope

This PR adds a Django Admin interface for triggering the existing workshop scraper. It does not modify the existing models, migrations, Docker setup, or scraper implementation.