This spike is about defining how and where people will be able to manage their automatic topic subscription preferences.
=== Context
Notifications are valuable to the extent they inform people when something happens they consider to be interesting and relevant.
Core to delivering on the above is ensuring people have easy access to settings that enable them to decide, with sufficient granularity, what events they do and do not want to be notified about.
This spike is about arriving at an initial opinion about what "easy access" and "sufficient granularity" mean in the context of automatic topic subscriptions.
=== Question(s) this spike should answer
[ ] Where is the preference for automatically subscribing to topics surfaced?
-- Is it exposed in `Special:Preferences` as a setting people interact with to govern how automatic topic subscriptions behave across all talk pages they engage with?
-- Is it exposed within the Reply and New Discussion Tools themselves thereby giving people the ability to opt-in/out of being automatically subscribed to a conversation on a case-by-case basis?
-- Are there settings in both places (e.g. a setting `Special:Preferences` and an additional setting within the tools for people to make ad-hoc adjustments to that global/default setting)?
=== Done
[] Answers to all `===Open questions` are documented in the task description
[] Tickets are created for any new work that emerges in the course of answering the `===Open questions` above