sync docs
sync docs from master after the 4.4.1 docs pass
publish three more docs, now that they no longer name a live deployment delivering-a-client-project, deploy-in-production and session-and-token-storage each carried one clause about the project's own playground. Two were asides in a CI-coverage note and are gone. The third was the clearest worked example of 'same site, different paths', so it is now a generic one rather than missing. Four docs stay withheld: one names a real exposure on a live deployment, two carry proof-of-concept and deployment detail, and one is a parked design argument.