fix: exec tool should not treat URLs as file paths

The guardCommand path check regex misidentifies URL components as
filesystem paths (e.g. `//example.com` from `https://example.com`),
causing commands like `curl https://...` to be blocked with
"path outside working dir".

Strip URLs from the command string before running path checks.

Fixes #386

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

pkg/tools/shell.go

@@ -188,8 +188,12 @@ func (t *ExecTool) guardCommand(command, cwd string) string {
 			return ""
 		}
 
+		// Strip URLs before path checking so they don't get misidentified as file paths
+		urlPattern := regexp.MustCompile(`[a-zA-Z][a-zA-Z0-9+.-]*://[^\s\"']+`)
+		stripped := urlPattern.ReplaceAllString(cmd, "")
+
 		pathPattern := regexp.MustCompile(`[A-Za-z]:\\[^\\\"']+|/[^\s\"']+`)
-		matches := pathPattern.FindAllString(cmd, -1)
+		matches := pathPattern.FindAllString(stripped, -1)
 
 		for _, raw := range matches {
 			p, err := filepath.Abs(raw)