docs: Fix typo in sequence diagram documentation

docs: Update sequence diagram descriptions for clarity

chore: Update architecture diagram in assets directory

docs: Update sequence diagram for newsletter automation flow

clarified role of GH config

article collection and typo fixes

article collection and typo fixes

docs: Improved system and add sequence diagrams

bugfix: update workflow schedule to run as mentioned in Readme again

chore: update package versions in dependencies list

small change: reverse RSS feed items from old to new

chore: update dependencies for enhanced compatibility

changed publication time

refactor: Move delay logic into `send_campaign_draft` and update dry-run handling

feat: add subject parameter to send_campaign function