refactor: split who.rs into who/ module (bd-2cbw)

Split 2447-line who.rs into focused submodules:
- who/scoring.rs: half_life_decay (20 lines)
- who/queries.rs: 5 query functions + helpers (~1400 lines)
- who/format.rs: human + JSON formatters (~570 lines)
- who.rs: slim module root with mode dispatch + re-exports (~260 lines)

All 1052 tests pass. No public API changes.

.beads/last-touched

@@ -1 +1 @@
-bd-9lbr
+bd-2cbw

src/cli/commands/who/format.rs

@@ -8,8 +8,8 @@ use crate::core::who_types::{
     ActiveResult, ExpertResult, OverlapResult, ReviewsResult, WhoResult, WorkloadResult,
 };
 
+use super::WhoRun;
 use super::queries::format_overlap_role;
-use super::{WhoRun, WhoResolvedInput};
 
 // ─── Human Output ────────────────────────────────────────────────────────────
 

src/cli/commands/who/queries.rs

@@ -320,7 +320,7 @@ fn build_mr_refs_for_user(conn: &Connection, ua: &UserAccum) -> Vec<String> {
 ///
 /// Parameters: `?1` = path, `?2` = since_ms, `?3` = project_id (nullable),
 ///             `?4` = as_of_ms, `?5` = closed_mr_multiplier, `?6` = reviewer_min_note_chars
-fn build_expert_sql_v2(is_prefix: bool) -> String {
+pub(super) fn build_expert_sql_v2(is_prefix: bool) -> String {
     let path_op = if is_prefix {
         "LIKE ?1 ESCAPE '\\'"
     } else {
@@ -967,7 +967,7 @@ pub fn query_reviews(
 }
 
 /// Normalize a raw review prefix like "Suggestion (non-blocking):" into "suggestion".
-fn normalize_review_prefix(raw: &str) -> String {
+pub(super) fn normalize_review_prefix(raw: &str) -> String {
     let s = raw.trim().trim_end_matches(':').trim().to_lowercase();
 
     // Strip "(non-blocking)" and similar parentheticals