Subgoal 2:  Use filecoin to back up my confused/corrupt data right now
   Reason: this lets me repurpose my harddrives and opens my options
   Concern: filecoin likes having a beefy system to run.  Many gigabytes
   of ram.
   [Side question: is there an existing hash database of operating system
   install images, pgp key fingerprints?  I'm quite sure that there's a
   timestamped merkle tree of OS images somewhere.  Maybe scan some
   blockchains for such things?]
   Question: are there public interfaces to filecoin, to preclude running
   a node?  I think a couple tutorials indicate this.
   Subgoal: visit filecoin tutorials, discern the 2 public filecoin nodes
   I vaguely recall them indicating.