fix: remove tab switching, filter AI thinking from responses

- Remove Tab/Shift+Tab for tab switching (use only Ctrl+T)
- Tab key now inserts tab character in chat/terminal input
- Filter <think...> blocks from AI responses (MiniMax etc.)
- Filter << >> reasoning blocks from AI responses

💘 Generated with Crush

Assisted-by: GLM-5.1 via Crush <crush@charm.land>

internal/orchestrator/orchestrator.go

@@ -6,6 +6,7 @@ import (
 	"fmt"
 	"io"
 	"net/http"
+	"regexp"
 	"strings"
 	"time"
 
@@ -127,7 +128,7 @@ func (o *Orchestrator) Send(userMessage string) (string, error) {
 		return "", fmt.Errorf("no response from AI")
 	}
 
-	content := chatResp.Choices[0].Message.Content
+	content := cleanAIResponse(chatResp.Choices[0].Message.Content)
 	o.history = append(o.history, Message{
 		Role:    "assistant",
 		Content: content,
@@ -222,6 +223,31 @@ func (o *Orchestrator) ClearHistory() {
 	o.Workflow.Reset()
 }
 
+func cleanAIResponse(content string) string {
+	thinkRe := regexp.MustCompile(`(?s)<[Tt]hink[^>]*>.*?</[Tt]hink>`)
+	content = thinkRe.ReplaceAllString(content, "")
+	lines := strings.Split(content, "\n")
+	var clean []string
+	inBlock := false
+	for _, line := range lines {
+		trimmed := strings.TrimSpace(line)
+		if trimmed == "<<" || trimmed == "<<<" {
+			inBlock = true
+			continue
+		}
+		if trimmed == ">>" || trimmed == ">>>" {
+			inBlock = false
+			continue
+		}
+		if inBlock {
+			continue
+		}
+		clean = append(clean, line)
+	}
+	result := strings.TrimSpace(strings.Join(clean, "\n"))
+	return result
+}
+
 func getProviderBaseURL(name string) string {
 	switch name {
 	case "minimax":