Improve Sourcegraph tool with context window and fix diagnostics

- Add context_window parameter to control code context display
- Fix LSP diagnostics notification handling with proper async waiting
- Switch to keyword search pattern for better results
- Add Sourcegraph tool to task agent

🤖 Generated with termai
Co-Authored-By: termai <noreply@termai.io>

cmd/lsp/main.go

@@ -1,4 +1,16 @@
 package main
 
+import (
+	"context"
+	"fmt"
+
+	"github.com/kujtimiihoxha/termai/internal/llm/tools"
+)
+
 func main() {
+	t := tools.NewSourcegraphTool()
+	r, _ := t.Run(context.Background(), tools.ToolCall{
+		Input: `{"query": "context.WithCancel lang:go"}`,
+	})
+	fmt.Println(r.Content)
 }