feat: review queue polish (pace, sort, type filter), drop unused phase-detection UI

Review Queue: show pace alongside distance/duration/HR, sort by activity
date (most recent first) instead of classification timestamp, and add a
filter by workout kind with a special "Unsorted" option for runs where
the rule engine found zero candidates at all (distinct from ambiguous
multi-candidate runs).

Profile: remove the phase-detection warm-up/cool-down section from the
UI -- not used by anything yet (phase segmentation is future work) and
was adding noise. The underlying fields are untouched so no data is lost
and the settings screen still round-trips them on save.

frontend/src/pages/Profile.tsx

@@ -146,36 +146,6 @@ export function Profile() {
         ))}
       </fieldset>
 
-      <fieldset className="kind-editor">
-        <legend>Phase detection (warm-up / cool-down minutes)</legend>
-        {(
-          [
-            ["Easy", "EasyWarmupMinutes", "EasyCooldownMinutes"],
-            ["Long", "LongWarmupMinutes", "LongCooldownMinutes"],
-            ["Tempo", "TempoWarmupMinutes", "TempoCooldownMinutes"],
-            ["Threshold 30'", "Threshold30WarmupMinutes", "Threshold30CooldownMinutes"],
-            ["Threshold 60'", "Threshold60WarmupMinutes", "Threshold60CooldownMinutes"],
-            ["MAS Test", "MASTestWarmupMinutes", "MASTestCooldownMinutes"],
-          ] as const
-        ).map(([label, warmupKey, cooldownKey]) => (
-          <div key={label} className="controls">
-            <NumberField
-              label={`${label} warm-up`}
-              value={profile[warmupKey]}
-              onChange={(v) => set(warmupKey, v)}
-            />
-            <NumberField
-              label={`${label} cool-down`}
-              value={profile[cooldownKey]}
-              onChange={(v) => set(cooldownKey, v)}
-            />
-          </div>
-        ))}
-        <p className="empty-state">
-          Interval workouts detect warm-up/cool-down from lap data directly and don't use these settings.
-        </p>
-      </fieldset>
-
       <button onClick={save}>Save</button>
     </div>
   );