Fix URL blocking in shell tool and orphaned tool result pairing

Strip URLs before path detection in shell guard so schemes like
https://... aren't incorrectly treated as file paths. Also fix
consecutive tool results from parallel calls being dropped as orphans.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

pkg/agent/context.go

@@ -230,7 +230,11 @@ func sanitizeHistoryForProvider(history []providers.Message) []providers.Message
 				continue
 			}
 			last := sanitized[len(sanitized)-1]
-			if last.Role != "assistant" || len(last.ToolCalls) == 0 {
+			// A tool result is valid if it follows either an assistant with
+			// tool calls, or another tool result (multiple consecutive results
+			// from parallel tool calls).
+			validPredecessor := (last.Role == "assistant" && len(last.ToolCalls) > 0) || last.Role == "tool"
+			if !validPredecessor {
 				logger.DebugCF("agent", "Dropping orphaned tool message", map[string]any{})
 				continue
 			}

pkg/tools/shell.go

@@ -290,8 +290,12 @@ func (t *ExecTool) guardCommand(command, cwd string) string {
 			return ""
 		}
 
+		// Strip URLs before path detection so schemes like https://... aren't
+		// treated as file paths.
+		cmdNoURLs := regexp.MustCompile(`[a-zA-Z][a-zA-Z0-9+.-]*://[^\s\"']+`).ReplaceAllString(cmd, "")
+
 		pathPattern := regexp.MustCompile(`[A-Za-z]:\\[^\\\"']+|/[^\s\"']+`)
-		matches := pathPattern.FindAllString(cmd, -1)
+		matches := pathPattern.FindAllString(cmdNoURLs, -1)
 
 		for _, raw := range matches {
 			p, err := filepath.Abs(raw)