dsh-error-doctor: One command to fix the 403 quota limit for installed DSH

The DSH adapter merges 403 errors into the authentication branch and places them before quota determination, causing the "free quota exhausted stops immediately" issue to be reported as an invalid key. The dsh-error-doctor maintained by mengge237 provides a read-only health check: it extracts the ordering function from the installed product, feeds it real 403 quota messages, and checks whether it returns QUOTA or AUTH, using the exit code to draw a conclusion (0 fixed, 1 still factory default, 2 unreadable). It does not read source code text or recognize comment line numbers; it only recognizes runtime behavior, therefore detecting patches applied by others. It has been empirically verified against the httpErrorCode of 0.1.5-rc.2 and the providerError of 0.1.7-alpha.2 and 0.1.7-rc.1. It can be used as a CLI (with --json for machine-readable output), installed as a plugin (tool name: dsh_error_doctor), or imported as a library (functions: findRoot, probeInstall, toolConfig). The entire process is read-only; it does not write files, send requests, or read keys. The 403 status in upstream 0.1.7-rc.1 is still ranked before quota determination.