Phase 5: TUI client (Bubbletea)

- cmd/tui/main.go: entry point with --server, --token, --version flags
- cmd/tui/config.go: config from ~/.config/dumpster/config.yaml or env vars
- cmd/tui/auth.go: login flow, session cookie management
- cmd/tui/api.go: HTTP client for servers, channels, messages, voice
- cmd/tui/model.go: root bubbletea model with state management
- cmd/tui/theme.go: Gruvbox dark lipgloss styles
- cmd/tui/servers.go: server bar with [D] style initials
- cmd/tui/channels.go: channel list with #text and 🔊 voice
- cmd/tui/chat.go: IRC-style message viewport with colored usernames
- cmd/tui/input.go: message input with > _ prompt
- cmd/tui/members.go: member list with ●/◐/○ status
- cmd/tui/ws.go: WebSocket client for real-time events
- cmd/tui/voice.go: voice state tracking and mute toggle
- cmd/tui/keys.go: vim-style keybindings (j/k, g/G, Tab, /, etc)
- cmd/tui/views.go: multi-pane layout rendering
- Makefile: added build-tui and run-tui targets
- go.mod/go.sum: added charmbracelet dependencies

cmd/tui/channels.go

@@ -0,0 +1,150 @@
+package main
+
+import (
+	"fmt"
+	"sort"
+	"strings"
+)
+
+// ChannelList renders the channel sidebar for a server.
+func ChannelList(channels []Channel, activeIdx, hoverIdx, width, height int) string {
+	if len(channels) == 0 {
+		return ChannelListStyle.
+			Width(width).
+			Height(height).
+			Render(HelpStyle.Render("  No channels"))
+	}
+
+	// Group channels by category
+	type catGroup struct {
+		name     string
+		channels []Channel
+	}
+	catOrder := make([]string, 0)
+	catMap := make(map[string]*catGroup)
+
+	for _, ch := range channels {
+		cat := ch.Category
+		if cat == "" {
+			cat = "general"
+		}
+		if _, ok := catMap[cat]; !ok {
+			catMap[cat] = &catGroup{name: cat}
+			catOrder = append(catOrder, cat)
+		}
+		catMap[cat].channels = append(catMap[cat].channels, ch)
+	}
+
+	// Stable sort categories
+	sort.Strings(catOrder)
+
+	// Build flat list for index mapping
+	var lines []string
+	flatIdx := 0
+
+	for _, catName := range catOrder {
+		group := catMap[catName]
+		lines = append(lines, CategoryStyle.Render(strings.ToUpper(group.name)))
+
+		for _, ch := range group.channels {
+			prefix := "  "
+			if ch.Type == "voice" {
+				prefix = VoiceChannelPrefix.Render("🔊 ")
+			} else {
+				prefix = TextChannelPrefix.Render("# ")
+			}
+
+			style := ChannelInactive
+			if flatIdx == activeIdx {
+				style = ChannelActive
+			} else if flatIdx == hoverIdx {
+				style = ChannelHover
+			}
+
+			label := ch.Name
+			if len(label) > width-6 {
+				label = label[:width-9] + "..."
+			}
+			lines = append(lines, style.Render(prefix+label))
+			flatIdx++
+		}
+	}
+
+	return ChannelListStyle.
+		Width(width).
+		Height(height).
+		Render(strings.Join(lines, "\n"))
+}
+
+// ChannelFlatIndex converts a (category, channel index in category) to flat index.
+func ChannelFlatIndex(channels []Channel, targetID string) int {
+	catOrder := getCatOrder(channels)
+	flatIdx := 0
+	for _, catName := range catOrder {
+		for _, ch := range groupByCategory(channels)[catName] {
+			if ch.ID == targetID {
+				return flatIdx
+			}
+			flatIdx++
+		}
+	}
+	return 0
+}
+
+// ChannelByFlatIndex returns the channel at a flat index in the grouped view.
+func ChannelByFlatIndex(channels []Channel, flatIdx int) *Channel {
+	catOrder := getCatOrder(channels)
+	idx := 0
+	for _, catName := range catOrder {
+		for _, ch := range groupByCategory(channels)[catName] {
+			if idx == flatIdx {
+				return &ch
+			}
+			idx++
+		}
+	}
+	return nil
+}
+
+func groupByCategory(channels []Channel) map[string][]Channel {
+	m := make(map[string][]Channel)
+	for _, ch := range channels {
+		cat := ch.Category
+		if cat == "" {
+			cat = "general"
+		}
+		m[cat] = append(m[cat], ch)
+	}
+	return m
+}
+
+func getCatOrder(channels []Channel) []string {
+	seen := make(map[string]bool)
+	var order []string
+	for _, ch := range channels {
+		cat := ch.Category
+		if cat == "" {
+			cat = "general"
+		}
+		if !seen[cat] {
+			seen[cat] = true
+			order = append(order, cat)
+		}
+	}
+	sort.Strings(order)
+	return order
+}
+
+// ChannelCount returns total number of channels (for navigation limits).
+func ChannelCount(channels []Channel) int {
+	return len(channels)
+}
+
+// formatChannelHeader renders the channel header for the chat pane.
+func formatChannelHeader(ch Channel) string {
+	icon := "#"
+	if ch.Type == "voice" {
+		icon = "🔊"
+	}
+	return fmt.Sprintf("%s %s", icon, ch.Name)
+}