feat: turn completion verbs, brief mode, UI polish

- Show "Baked for 5s" / "Churned for 12s" when query completes
- Brief mode toggle via /brief
- Turn completion verbs from Claude Code (Baked, Brewed, Cogitated, etc.)
- 66 slash commands, 6600+ lines Go

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

Author: idoubi

internal/theme/spinners.go

@@ -71,6 +71,17 @@ func RandomVerb() string {
 	return SpinnerVerbs[rng.Intn(len(SpinnerVerbs))]
 }
 
+// TurnCompletionVerbs are past-tense verbs shown when a query completes
+var TurnCompletionVerbs = []string{
+	"Baked", "Brewed", "Churned", "Cogitated", "Cooked",
+	"Crunched", "Worked", "Crafted", "Forged", "Polished",
+}
+
+// RandomCompletionVerb returns a random completion verb
+func RandomCompletionVerb() string {
+	return TurnCompletionVerbs[rng.Intn(len(TurnCompletionVerbs))]
+}
+
 // ToolVerb returns an appropriate verb for a specific tool
 func ToolVerb(toolName string) string {
 	switch toolName {

internal/tui/model.go

@@ -427,6 +427,16 @@ func (m *Model) Update(msg tea.Msg) (tea.Model, tea.Cmd) {
 		m.streamingText.Reset()
 		m.activeTools = nil
 		m.thinkingText = ""
+		// Show completion message with duration
+		if m.queryStartTime != (time.Time{}) {
+			elapsed := time.Since(m.queryStartTime)
+			verb := theme.RandomCompletionVerb()
+			m.blocks = append(m.blocks, DisplayBlock{
+				Type:      "system",
+				Content:   fmt.Sprintf("%s for %s", verb, formatDuration(elapsed)),
+				Timestamp: time.Now(),
+			})
+		}
 		m.refreshViewport()
 		m.input.Focus()
 		// Ring terminal bell to notify user