feat: replace mapping text input with company dropdown selector

- Add proxy endpoint GET /api/admin/digital-twin/companies
- Fetch company list from digital-twin API on modal open
- Select dropdown shows company name + industry type
- Remove manual UUID input in favor of selection

dashboard/app/globals.css

@@ -480,6 +480,19 @@ a {
   padding: 0 24px;
 }
 
+.loading-inline {
+  display: flex;
+  align-items: center;
+  gap: 8px;
+  padding: 10px 0;
+  font-size: 13px;
+  color: var(--md-on-surface-variant);
+}
+
+.loading-inline .material-symbols-outlined {
+  font-size: 18px;
+}
+
 /* ===== Login ===== */
 .login-container {
   min-height: 100vh;

dashboard/app/page.tsx

@@ -1,12 +1,18 @@
 'use client';
 
-import { useState } from 'react';
+import { useState, useEffect } from 'react';
 import { useRouter } from 'next/navigation';
 import { useAuth } from '@/lib/auth-context';
 import { useTenants } from '@/lib/hooks';
 import { Card } from '@/components/Card';
 import { api } from '@/lib/api';
-import { Tenant } from '@/lib/types';
+import type { Tenant } from '@/lib/types';
+
+interface DigitalTwinCompany {
+  companyId: string;
+  name: string;
+  industryType: string;
+}
 
 export default function HomePage() {
   const { user, logout } = useAuth();
@@ -25,6 +31,17 @@ export default function HomePage() {
     companyId: '',
   });
   const [isSaving, setIsSaving] = useState(false);
+  const [dtCompanies, setDtCompanies] = useState<DigitalTwinCompany[]>([]);
+  const [companiesLoading, setCompaniesLoading] = useState(false);
+
+  useEffect(() => {
+    if (!mappingModal.open) return;
+    setCompaniesLoading(true);
+    api.get<{ companies: DigitalTwinCompany[] }>('/api/admin/digital-twin/companies')
+      .then((res) => setDtCompanies(res.companies))
+      .catch(() => setDtCompanies([]))
+      .finally(() => setCompaniesLoading(false));
+  }, [mappingModal.open]);
 
   const handleTenantSelect = (tenantId: string) => {
     router.push(`/${tenantId}`);
@@ -136,30 +153,30 @@ export default function HomePage() {
 
             <div className="modal-body-form">
               <div className="form-field">
-                <label>디지털 트윈 회사 ID</label>
-                <input
-                  type="text"
-                  value={mappingModal.companyId}
-                  onChange={(e) => setMappingModal((prev) => ({ ...prev, companyId: e.target.value }))}
-                  placeholder="회사 UUID (예: 7f5c058c-...)"
-                  autoFocus
-                />
+                <label>디지털 트윈 회사</label>
+                {companiesLoading ? (
+                  <div className="loading-inline">
+                    <span className="material-symbols-outlined spinning">progress_activity</span>
+                    회사 목록 로딩 중...
+                  </div>
+                ) : (
+                  <select
+                    value={mappingModal.companyId}
+                    onChange={(e) => setMappingModal((prev) => ({ ...prev, companyId: e.target.value }))}
+                    autoFocus
+                  >
+                    <option value="">선택 안 함</option>
+                    {dtCompanies.map((c) => (
+                      <option key={c.companyId} value={c.companyId}>
+                        {c.name} ({c.industryType})
+                      </option>
+                    ))}
+                  </select>
+                )}
               </div>
             </div>
 
             <div className="modal-actions">
-              {mappingModal.companyId && (
-                <button 
-                  className="btn-outline btn-danger"
-                  onClick={() => {
-                    setMappingModal((prev) => ({ ...prev, companyId: '' }));
-                  }}
-                  disabled={isSaving}
-                  style={{ marginRight: 'auto' }}
-                >
-                  매핑 해제
-                </button>
-              )}
               <button 
                 className="btn-text"
                 onClick={() => setMappingModal((prev) => ({ ...prev, open: false }))}

main.py

@@ -155,6 +155,39 @@ async def update_tenant_digital_twin_mapping(
         raise HTTPException(status_code=400, detail=str(e))
 
 
+@app.get("/api/admin/digital-twin/companies")
+async def list_digital_twin_companies(
+    current_user: TokenData = Depends(require_superadmin),
+):
+    import httpx
+
+    api_url = os.getenv("DIGITAL_TWIN_API_URL", "")
+    if not api_url:
+        raise HTTPException(
+            status_code=503, detail="DIGITAL_TWIN_API_URL not configured"
+        )
+    try:
+        async with httpx.AsyncClient(timeout=10.0) as client:
+            resp = await client.get(f"{api_url}/api/v1/companies")
+            resp.raise_for_status()
+            data = resp.json()
+            companies = data.get("data", [])
+            return {
+                "companies": [
+                    {
+                        "companyId": c.get("companyId"),
+                        "name": c.get("name"),
+                        "industryType": c.get("industryType"),
+                    }
+                    for c in companies
+                ]
+            }
+    except httpx.HTTPError as e:
+        raise HTTPException(
+            status_code=502, detail=f"Failed to fetch from digital-twin: {e}"
+        )
+
+
 if __name__ == "__main__":
     import uvicorn