Update for 0.4.2, crates.io libraries, mumbot move and Epic 3 plan
docs: update wiki for 0.4.1 and the upcoming 0.4.2 macOS signing and notarization, keychain and microphone prompts, late-join repeat announcements in the screen share and watch party flows, CI change detection, Dependabot and the apt mirror fallback.
docs: update wiki for 0.4.0 and upcoming 0.4.1
Mark stage 1b as released in 0.2.0, detail stage 1d, describe sharded E2E
Update wiki for new features, releases and branch protection
Add project wiki: features, installation, building, development, testing, architecture, troubleshooting, spec and dev workflow