executeMetaquery error handling closes #4789 (#4834)

* Add test for #4789: executeMetaquery panic instead of error

Added TestExecuteMetaquery_NotInitialised to demonstrate the bug where
executeMetaquery panics with "client is not initalised" instead of
returning an error when called before initialization completes.

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude <noreply@anthropic.com>

* Fix #4789: Return error instead of panic in executeMetaquery

Replace panic("client is not initalised") with proper error return
in executeMetaquery. This prevents unrecoverable crashes when the
method is called before client initialization completes.

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude <noreply@anthropic.com>

---------

Co-authored-by: Claude <noreply@anthropic.com>

pkg/interactive/interactive_client.go

@@ -513,7 +513,7 @@ func (c *InteractiveClient) getQuery(ctx context.Context, line string) *modconfi
 func (c *InteractiveClient) executeMetaquery(ctx context.Context, query string) error {
 	// the client must be initialised to get here
 	if !c.isInitialised() {
-		panic("client is not initalised")
+		return fmt.Errorf("client is not initialised")
 	}
 	// validate the metaquery arguments
 	validateResult := metaquery.Validate(query)

pkg/interactive/interactive_client_test.go

@@ -1,6 +1,7 @@
 package interactive
 
 import (
+	"context"
 	"strings"
 	"sync"
 	"testing"
@@ -630,3 +631,27 @@ func TestGetQueryInfo_FromDetection(t *testing.T) {
 		})
 	}
 }
+
+// TestExecuteMetaquery_NotInitialised tests that executeMetaquery returns
+// an error instead of panicking when the client is not initialized.
+//
+// Bug: #4789
+func TestExecuteMetaquery_NotInitialised(t *testing.T) {
+	// Create an InteractiveClient that is not initialized
+	c := &InteractiveClient{}
+	c.initialisationComplete.Store(false)
+
+	ctx := context.Background()
+
+	// Attempt to execute a metaquery before initialization
+	// This should return an error, not panic
+	err := c.executeMetaquery(ctx, ".inspect")
+
+	// We expect an error
+	if err == nil {
+		t.Error("Expected error when executing metaquery before initialization, but got nil")
+	}
+
+	// The test passes if we get here without a panic
+	t.Logf("Successfully received error instead of panic: %v", err)
+}