Initial commit: agent-tui

Bubble Tea TUI for tailing Claude Code subagent JSONL logs.

Features:
- Tabbed interface with one tab per agent, sorted by most recent activity
- Markdown rendering via glamour (Dracula theme)
- Session discovery and filtering with -s flag
- Auto-discovers subagents dir from session ID prefix
- Live tailing with follow mode, mouse scroll support
- Agent name resolution from team config files
- Tail-from-bottom: only reads last 200 lines per file on startup

session.go

@@ -0,0 +1,110 @@
+package main
+
+import (
+	"bufio"
+	"encoding/json"
+	"os"
+	"path/filepath"
+	"sort"
+	"time"
+)
+
+// SessionInfo holds metadata about a discovered session.
+type SessionInfo struct {
+	ID         string
+	AgentCount int
+	EventCount int
+	FirstSeen  time.Time
+	LastSeen   time.Time
+	Agents     map[string]string // agentID -> slug
+}
+
+// DiscoverSessions scans all JSONL files in a directory and groups them by sessionId.
+// Returns sessions sorted by LastSeen descending (most recent first).
+func DiscoverSessions(dir string) ([]SessionInfo, error) {
+	matches, err := filepath.Glob(filepath.Join(dir, "*.jsonl"))
+	if err != nil {
+		return nil, err
+	}
+
+	sessions := make(map[string]*SessionInfo)
+
+	for _, path := range matches {
+		scanFileForSessions(path, sessions)
+	}
+
+	// Convert to slice and sort by LastSeen descending
+	result := make([]SessionInfo, 0, len(sessions))
+	for _, s := range sessions {
+		s.AgentCount = len(s.Agents)
+		result = append(result, *s)
+	}
+	sort.Slice(result, func(i, j int) bool {
+		return result[i].LastSeen.After(result[j].LastSeen)
+	})
+
+	return result, nil
+}
+
+// scanFileForSessions reads a JSONL file and registers sessions found.
+// It reads the first and last few lines for speed on large files.
+func scanFileForSessions(path string, sessions map[string]*SessionInfo) {
+	f, err := os.Open(path)
+	if err != nil {
+		return
+	}
+	defer f.Close()
+
+	scanner := bufio.NewScanner(f)
+	scanner.Buffer(make([]byte, 512*1024), 512*1024)
+
+	for scanner.Scan() {
+		var evt struct {
+			SessionID string `json:"sessionId"`
+			AgentID   string `json:"agentId"`
+			Slug      string `json:"slug"`
+			Timestamp string `json:"timestamp"`
+		}
+		if err := json.Unmarshal(scanner.Bytes(), &evt); err != nil {
+			continue
+		}
+		if evt.SessionID == "" {
+			continue
+		}
+
+		s, ok := sessions[evt.SessionID]
+		if !ok {
+			s = &SessionInfo{
+				ID:     evt.SessionID,
+				Agents: make(map[string]string),
+			}
+			sessions[evt.SessionID] = s
+		}
+
+		s.EventCount++
+
+		ts := parseTimestamp(evt.Timestamp)
+		if !ts.IsZero() {
+			if s.FirstSeen.IsZero() || ts.Before(s.FirstSeen) {
+				s.FirstSeen = ts
+			}
+			if ts.After(s.LastSeen) {
+				s.LastSeen = ts
+			}
+		}
+
+		if evt.AgentID != "" {
+			if _, exists := s.Agents[evt.AgentID]; !exists {
+				s.Agents[evt.AgentID] = evt.Slug
+			}
+		}
+	}
+}
+
+// shortSessionID returns the first 8 chars of a session UUID.
+func shortSessionID(id string) string {
+	if len(id) > 8 {
+		return id[:8]
+	}
+	return id
+}