fix(interactivity): Prompt formatting

[rts1-godaddy]

Summary

• Fix the prompt formatting to include a : at the end.

Test plan

• cargo fmt --all --check
• cargo clippy --all-targets -- -D warnings
• cargo test --all-targets

Manual verification

Setup:

# In the cli repo, temporarily override the engine dependency:
cd cli/rust
# Edit Cargo.toml → cli-engine = { features = ["pkce-auth"], path = "../../cli-engine" }
cargo build --release && cp target/release/gddy ~/.local/bin/gddy

Test WITHOUT the fix (baseline):

cd cli-engine && git checkout main
cd cli/rust && cargo build --release && cp target/release/gddy ~/.local/bin/gddy
# <command to reproduce the issue>
# Expected: <describe broken behavior>

Test WITH the fix:

cd cli-engine && git checkout <this-branch>
cd cli/rust && cargo build --release && cp target/release/gddy ~/.local/bin/gddy
# <same command>
# Expected: <describe fixed behavior>

Cleanup:

# Revert cli/rust/Cargo.toml back to:
# cli-engine = { features = ["pkce-auth"], version = "<published-version>" }

[jpage-godaddy]

Needs the PR title fixed to match what conventional commit needs; I would make this a fix(interactivity): prefix, something like that