feat: add server-side session filtering with input bytes and human score

Replace client-side session table filtering with server-side filtering
via a new /fragments/recent-sessions htmx endpoint. Add InputBytes column
to session tables, Human score > 0 checkbox filter, and Sort by Input
Bytes option to help identify sessions with actual shell interaction.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

internal/storage/memstore.go

@@ -336,10 +336,26 @@ func (m *MemoryStore) GetRecentSessions(_ context.Context, limit int, activeOnly
 	m.mu.Lock()
 	defer m.mu.Unlock()
 
-	// Count events per session.
+	return m.collectSessions(limit, activeOnly, DashboardFilter{}), nil
+}
+
+func (m *MemoryStore) GetFilteredSessions(_ context.Context, limit int, activeOnly bool, f DashboardFilter) ([]Session, error) {
+	m.mu.Lock()
+	defer m.mu.Unlock()
+
+	return m.collectSessions(limit, activeOnly, f), nil
+}
+
+// collectSessions gathers sessions matching filter criteria. Must be called with m.mu held.
+func (m *MemoryStore) collectSessions(limit int, activeOnly bool, f DashboardFilter) []Session {
+	// Compute event counts and input bytes per session.
 	eventCounts := make(map[string]int)
+	inputBytes := make(map[string]int64)
 	for _, e := range m.SessionEvents {
 		eventCounts[e.SessionID]++
+		if e.Direction == 0 {
+			inputBytes[e.SessionID] += int64(len(e.Data))
+		}
 	}
 
 	var sessions []Session
@@ -347,17 +363,54 @@ func (m *MemoryStore) GetRecentSessions(_ context.Context, limit int, activeOnly
 		if activeOnly && s.DisconnectedAt != nil {
 			continue
 		}
+		if !matchesSessionFilter(s, f) {
+			continue
+		}
 		sess := *s
 		sess.EventCount = eventCounts[s.ID]
+		sess.InputBytes = inputBytes[s.ID]
 		sessions = append(sessions, sess)
 	}
-	sort.Slice(sessions, func(i, j int) bool {
-		return sessions[i].ConnectedAt.After(sessions[j].ConnectedAt)
-	})
+
+	if f.SortBy == "input_bytes" {
+		sort.Slice(sessions, func(i, j int) bool {
+			return sessions[i].InputBytes > sessions[j].InputBytes
+		})
+	} else {
+		sort.Slice(sessions, func(i, j int) bool {
+			return sessions[i].ConnectedAt.After(sessions[j].ConnectedAt)
+		})
+	}
+
 	if limit > 0 && len(sessions) > limit {
 		sessions = sessions[:limit]
 	}
-	return sessions, nil
+	return sessions
+}
+
+// matchesSessionFilter returns true if the session matches the given filter.
+func matchesSessionFilter(s *Session, f DashboardFilter) bool {
+	if f.Since != nil && s.ConnectedAt.Before(*f.Since) {
+		return false
+	}
+	if f.Until != nil && s.ConnectedAt.After(*f.Until) {
+		return false
+	}
+	if f.IP != "" && s.IP != f.IP {
+		return false
+	}
+	if f.Country != "" && s.Country != f.Country {
+		return false
+	}
+	if f.Username != "" && s.Username != f.Username {
+		return false
+	}
+	if f.HumanScoreAboveZero {
+		if s.HumanScore == nil || *s.HumanScore <= 0 {
+			return false
+		}
+	}
+	return true
 }
 
 func (m *MemoryStore) GetTopExecCommands(_ context.Context, limit int) ([]TopEntry, error) {