chore: Move `ContinueMode` and `LogPrefix` to `turborepo-types` (#11338)
## Summary
- Moves `ContinueMode` enum from `turborepo-lib/src/cli/mod.rs` to
`turborepo-types`
- Moves `LogPrefix` enum from `turborepo-lib/src/cli/mod.rs` to
`turborepo-types`
- Updates all imports across turborepo-lib to use `turborepo_types::`
directly
This continues the modularization effort to extract types from the
monolithic `turborepo-lib` crate into smaller, focused crates.
## Test Plan
- `cargo build -p turborepo-lib` passes with no errors or warnings