Fault tolerance docs

This epic is to track updates and doc bugs across the fault tolerance docs.

Notes from a conversation with Andrew Rouse about things that would be helpful to include in the fault tolerance docs:

• The location of the javadoc and spec (the spec's job generally is to describe how the implementation must behave, and users' questions usually boil down to "how does the implementation behave when I do this?" or "why is the implementation doing this when I do that?" or "how do I make it do something else")
• Maybe a couple more examples
• The execution flow diagrams
• The event tracing
• A list of common pitfalls

Start by reviewing the existing fault tolerance documentation and the listed notes. Identify the relevant Javadoc and specification locations, then determine which examples, execution-flow diagrams, event tracing details, and common pitfalls are missing. Done means the fault tolerance documentation has been updated to cover the agreed scope.