refactor: extract who result types to core::who_types for TUI reuse

Move the 14 result structs and enums (WhoResult, ExpertResult, Expert,
ScoreComponents, ExpertMrDetail, WorkloadResult, WorkloadIssue, WorkloadMr,
WorkloadDiscussion, ReviewsResult, ReviewCategory, ActiveResult,
ActiveDiscussion, OverlapResult, OverlapUser) from cli::commands::who into
a new core::who_types module.

The TUI Who screen needs these types to render results, but importing from
the CLI layer would create a circular dependency (TUI -> CLI -> core). By
placing them in core, both the CLI and TUI can depend on them cleanly.

The CLI module re-exports all types via `pub use crate::core::who_types::*`
so existing consumers are unaffected.

src/core/mod.rs

@@ -22,6 +22,7 @@ pub mod timeline_collect;
 pub mod timeline_expand;
 pub mod timeline_seed;
 pub mod trace;
+pub mod who_types;
 
 pub use config::Config;
 pub use error::{LoreError, Result};