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/store.go

@@ -29,6 +29,7 @@ type Session struct {
 	HumanScore     *float64
 	ExecCommand    *string
 	EventCount     int
+	InputBytes     int64
 }
 
 // SessionLog represents a single log entry for a session.
@@ -76,11 +77,13 @@ type CountryCount struct {
 
 // DashboardFilter contains optional filters for dashboard queries.
 type DashboardFilter struct {
-	Since    *time.Time
-	Until    *time.Time
-	IP       string
-	Country  string
-	Username string
+	Since              *time.Time
+	Until              *time.Time
+	IP                 string
+	Country            string
+	Username           string
+	HumanScoreAboveZero bool
+	SortBy             string
 }
 
 // TopEntry represents a value and its count for top-N queries.
@@ -137,6 +140,10 @@ type Store interface {
 	// If activeOnly is true, only sessions with no disconnected_at are returned.
 	GetRecentSessions(ctx context.Context, limit int, activeOnly bool) ([]Session, error)
 
+	// GetFilteredSessions returns sessions matching the given filter, ordered
+	// by the filter's SortBy field (default: connected_at DESC).
+	GetFilteredSessions(ctx context.Context, limit int, activeOnly bool, f DashboardFilter) ([]Session, error)
+
 	// GetSession returns a single session by ID.
 	GetSession(ctx context.Context, sessionID string) (*Session, error)