refactor(who): make --limit optional (unlimited default) and fix clippy sort lints

Change the `who` command's --limit flag from default=20 to optional,
so omitting it returns all results. This matches the behavior users
expect when they want a complete expert/workload/active/overlap listing
without an arbitrary cap.

Also applies clippy-recommended sort improvements:
- who/reviews: sort_by(|a,b| b.count.cmp(&a.count)) -> sort_by_key with Reverse
- drift: same pattern for frequency sorting

Adds Theme::color_icon() helper to DRY the stage-icon coloring pattern
used in sync output (was inline closure, now shared method).

src/cli/commands/drift.rs

@@ -382,7 +382,7 @@ fn extract_drift_topics(description: &str, notes: &[NoteRow], drift_idx: usize)
     }
 
     let mut sorted: Vec<(String, usize)> = freq.into_iter().collect();
-    sorted.sort_by(|a, b| b.1.cmp(&a.1));
+    sorted.sort_by_key(|b| std::cmp::Reverse(b.1));
 
     sorted
         .into_iter()

src/cli/commands/who/mod.rs

@@ -143,6 +143,8 @@ pub fn run_who(config: &Config, args: &WhoArgs) -> Result<WhoRun> {
         "none"
     };
 
+    let limit = args.limit.map_or(usize::MAX, usize::from);
+
     match mode {
         WhoMode::Expert { path } => {
             // Compute as_of first so --since durations are relative to it.
@@ -159,7 +161,6 @@ pub fn run_who(config: &Config, args: &WhoArgs) -> Result<WhoRun> {
             } else {
                 resolve_since_from(args.since.as_deref(), "24m", as_of_ms)?
             };
-            let limit = usize::from(args.limit);
             let result = expert::query_expert(
                 &conn,
                 &path,
@@ -191,7 +192,7 @@ pub fn run_who(config: &Config, args: &WhoArgs) -> Result<WhoRun> {
                 .as_deref()
                 .map(resolve_since_required)
                 .transpose()?;
-            let limit = usize::from(args.limit);
+
             let result = workload::query_workload(
                 &conn,
                 username,
@@ -231,7 +232,7 @@ pub fn run_who(config: &Config, args: &WhoArgs) -> Result<WhoRun> {
         }
         WhoMode::Active => {
             let since_ms = resolve_since(args.since.as_deref(), "7d")?;
-            let limit = usize::from(args.limit);
+
             let result =
                 active::query_active(&conn, project_id, since_ms, limit, args.include_closed)?;
             Ok(WhoRun {
@@ -249,7 +250,7 @@ pub fn run_who(config: &Config, args: &WhoArgs) -> Result<WhoRun> {
         }
         WhoMode::Overlap { path } => {
             let since_ms = resolve_since(args.since.as_deref(), "30d")?;
-            let limit = usize::from(args.limit);
+
             let result = overlap::query_overlap(&conn, &path, project_id, since_ms, limit)?;
             Ok(WhoRun {
                 resolved_input: WhoResolvedInput {

src/cli/commands/who/reviews.rs

@@ -105,7 +105,7 @@ pub(super) fn query_reviews(
         })
         .collect();
 
-    categories.sort_by(|a, b| b.count.cmp(&a.count));
+    categories.sort_by_key(|b| std::cmp::Reverse(b.count));
 
     Ok(ReviewsResult {
         username: username.to_string(),

src/cli/commands/who/types.rs

@@ -18,7 +18,7 @@ pub struct WhoResolvedInput {
     pub since_iso: Option<String>,
     /// "default" (mode default applied), "explicit" (user provided --since), "none" (no window)
     pub since_mode: String,
-    pub limit: u16,
+    pub limit: Option<u16>,
 }
 
 /// Top-level result enum -- one variant per mode.

src/cli/commands/who_tests.rs

@@ -286,7 +286,7 @@ fn test_is_file_path_discrimination() {
             reviews: false,
             since: None,
             project: None,
-            limit: 20,
+            limit: None,
             detail: false,
             no_detail: false,
             fields: None,
@@ -310,7 +310,7 @@ fn test_is_file_path_discrimination() {
             reviews: false,
             since: None,
             project: None,
-            limit: 20,
+            limit: None,
             detail: false,
             no_detail: false,
             fields: None,
@@ -334,7 +334,7 @@ fn test_is_file_path_discrimination() {
             reviews: false,
             since: None,
             project: None,
-            limit: 20,
+            limit: None,
             detail: false,
             no_detail: false,
             fields: None,
@@ -358,7 +358,7 @@ fn test_is_file_path_discrimination() {
             reviews: true,
             since: None,
             project: None,
-            limit: 20,
+            limit: None,
             detail: false,
             no_detail: false,
             fields: None,
@@ -382,7 +382,7 @@ fn test_is_file_path_discrimination() {
             reviews: false,
             since: None,
             project: None,
-            limit: 20,
+            limit: None,
             detail: false,
             no_detail: false,
             fields: None,
@@ -406,7 +406,7 @@ fn test_is_file_path_discrimination() {
             reviews: false,
             since: None,
             project: None,
-            limit: 20,
+            limit: None,
             detail: false,
             no_detail: false,
             fields: None,
@@ -431,7 +431,7 @@ fn test_detail_rejected_outside_expert_mode() {
         reviews: false,
         since: None,
         project: None,
-        limit: 20,
+        limit: None,
         detail: true,
         no_detail: false,
         fields: None,
@@ -460,7 +460,7 @@ fn test_detail_allowed_in_expert_mode() {
         reviews: false,
         since: None,
         project: None,
-        limit: 20,
+        limit: None,
         detail: true,
         no_detail: false,
         fields: None,