v1.2.1 - Optimize builds

Repoprompt can now be FULLY run -- client AND backend -- on your local or remote machine with the single command

./repoprompt.amd64

or for M-series mac or recent Raspberry Pis

./repoprompt.arm64

This release adds

[profile.release]
opt-level = 3
lto = true
strip = true
codegen-units = 1
panic = "abort"

to Cargo.toml for even faster execution speed and smaller binaries.