main
bootstrap: Remove bootstrap-btn file and refs.
shared: Move icons to web/images/icons.
web: Add explicit extensions to imports.
portico: Remove Bootstrap dependency from API/policies pages.
integrations: Drop Bootstrap and legacy CSS for modern bundle.
marketing_page: Clean up legacy portico header cruft.
portico: Load portico_variables.css on all portico pages.
portico: Establish and reference legacy portico bundle.