FIPS v0.2.0

Update changelog, version, and design docs for v0.2.0

Bump version to 0.2.0 and finalize changelog with discovery rework,
Tor transport, connect/disconnect commands, reproducible builds, and
12 bug fixes.

Update design documentation for discovery protocol rework:
- fips-wire-formats.md: remove visited bloom filter from LookupRequest,
  update size calculations
- fips-mesh-operation.md: replace flooding description with bloom-guided
  tree routing, add retry/backoff/rate-limiting subsections
- fips-configuration.md: add 5 new discovery config parameters, update
  control socket description for connect/disconnect commands

FIPS v0.1.0