fix(ground): WSL에서 지반 생성 Python·DWG 변환 실행 경로 해결

- 공통 resolvePython: Windows venv → .venv/bin/python → PIERZAINER_PYTHON → python3/python
- 지반 생성·수량산출 Excel·DWG 출력 서버가 같은 해석기 사용, ENOENT 안내 문구 보강
- WSL에서 번들 dwg2dxf.exe 호출 시 wslpath -w로 경로 변환, .exe 실행 권한 부여
- 실제 운곡교 DWG+Excel로 엔진/HTTP 경로 생성 확인(교각16·지형6,545점)

Co-Authored-By: Claude Haiku 5.5 <noreply@anthropic.com>

pierzainer_ground/ground-link-server.ts

@@ -4,6 +4,7 @@ import { existsSync } from 'node:fs';
 import path from 'node:path';
 import { randomUUID } from 'node:crypto';
 import type { Plugin } from 'vite';
+import { resolvePython,describeSpawnError } from './python-runtime.ts';
 export const GROUND_LINK_API='/__pierzainer/ground-link';
 export function startGroundBat(bat:string,context:string,cwd:string){
  return spawn(process.env.ComSpec??'cmd.exe',['/d','/s','/c',`""${bat}""`],{cwd,windowsHide:true,windowsVerbatimArguments:true,env:{...process.env,PIERZAINER_GROUND_CONTEXT:context},stdio:'ignore'});
@@ -42,10 +43,10 @@ export function groundLinkPlugin(root:string):Plugin{
     if(!existsSync(drawing)||!/\.(dwg|dxf)$/i.test(drawing)||drawing!==original&&!cached(drawing))throw new Error('종평면도를 선택하세요.');
     if(!existsSync(piers)||!/\.xlsx$/i.test(piers)||!cached(piers))throw new Error('교각 Excel을 선택하세요.');
     const id=randomUUID(),output=path.join(base,'data/output',`app_${id}`),job={output,logs:'',state:'running'};jobs.set(id,job);
-    const python=existsSync(path.join(base,'.venv/Scripts/python.exe'))?path.join(base,'.venv/Scripts/python.exe'):'python';
+    const python=resolvePython(root);
     const child=spawn(python,['-B','-u','-X','utf8','-m','pierzainer_ground.web_job',drawing,piers,output],{cwd:base,windowsHide:true,stdio:['ignore','pipe','pipe']});
     const append=(data:Buffer)=>{job.logs=(job.logs+data.toString('utf8')).slice(-200000);};child.stdout.on('data',append);child.stderr.on('data',append);
-    child.once('error',error=>{job.state='error';job.logs+='\n'+error.message;});child.once('close',code=>{job.state=code===0?'done':'error';});reply(200,{id});return;
+    child.once('error',error=>{job.state='error';job.logs+='\n'+describeSpawnError(error,python);});child.once('close',code=>{job.state=code===0?'done':'error';});reply(200,{id});return;
    }
    if(action==='result'){
     const job=jobs.get(body.id);if(!job)throw new Error('지반 생성 작업을 찾을 수 없습니다.');