fix/feat: Oracle thick mode 错误提示优化 + 向导步骤加载动画

- sync_adapters: thick mode 失败时抛出明确错误（含路径提示和操作指引）
  路径不存在时提前检测并打印日志，不再静默吞异常
- main.py: 应用启动时提前初始化 Oracle thick mode 并输出日志
- DataSyncPage: 新建任务向导步骤间加载动画
  Step0→1 获取表列表时显示半透明覆盖层 + 转圈 + 提示文字
  Step1→2 切换时显示过渡动画
  预览数据时右侧区域显示加载状态（转圈 + 说明文字）
  下一步/上一步按钮加载期间自动禁用防重复触发

backend/app/main.py

+import logging
 from contextlib import asynccontextmanager
 from fastapi import FastAPI
 from fastapi.middleware.cors import CORSMiddleware
@@ -6,10 +7,23 @@ from app.api.routes import patients, trials, matching, notifications, diagnoses
 from app.api.routes import auth, users, roles, permissions, departments
 from app.api.routes import batch_matching, sync, connection_profiles, dashboard
 
+logger = logging.getLogger(__name__)
+
 
 @asynccontextmanager
 async def lifespan(app: FastAPI):
     await init_db()
+    # 提前初始化 Oracle thick mode，启动时即可确认是否配置正确
+    try:
+        import oracledb
+        from app.services.sync_adapters import _init_oracle_thick_mode
+        ok = _init_oracle_thick_mode()
+        if ok:
+            logger.info("Oracle Instant Client 已加载（thick mode 启用）")
+        else:
+            logger.warning("Oracle Instant Client 未加载，Oracle 连接将使用 thin mode（不支持旧版 Oracle）")
+    except Exception:
+        pass
     yield
 
 

backend/app/services/sync_adapters.py

@@ -268,17 +268,28 @@ def _init_oracle_thick_mode() -> bool:
     oracledb can only be initialized once per process, so we guard with is_thin_mode().
     """
     import os
+    import logging
     import oracledb
+    _logger = logging.getLogger(__name__)
+
     if not oracledb.is_thin_mode():
         return True  # already thick
+
     client_path = os.environ.get("ORACLE_CLIENT_PATH", "").strip()
+    if client_path and not os.path.isdir(client_path):
+        _logger.error(
+            "Oracle Instant Client 路径不存在或不是目录: %r，请检查 ORACLE_CLIENT_PATH 环境变量", client_path
+        )
+        return False
+
     try:
         if client_path:
             oracledb.init_oracle_client(lib_dir=client_path)
         else:
             oracledb.init_oracle_client()   # search PATH / LD_LIBRARY_PATH
         return True
-    except Exception:
+    except Exception as e:
+        _logger.error("Oracle Instant Client 加载失败: %s", e)
         return False
 
 
@@ -287,17 +298,30 @@ def _create_oracle_engine(host: str, port: str, database: str,
                            oracle_type: str = "sid", pool_timeout: int = 8):
     """Build a SQLAlchemy engine for Oracle, handling SID vs service name.
 
-    Tries thick mode first (wider DB version support); falls back to thin mode.
-    Thick mode requires Oracle Instant Client — set ORACLE_CLIENT_PATH env var
-    to point to the directory containing oci.dll / libclntsh.so.
+    Requires thick mode (Oracle Instant Client). Set ORACLE_CLIENT_PATH env var
+    to point to the directory containing oci.dll / libclntsh.so, then restart
+    the backend via PowerShell so the env var is inherited.
     """
+    import os
+    import oracledb
     from sqlalchemy import create_engine
     from urllib.parse import quote_plus
-    _init_oracle_thick_mode()          # no-op if already thick or client missing
+
+    _init_oracle_thick_mode()
+
+    if oracledb.is_thin_mode():
+        client_path = os.environ.get("ORACLE_CLIENT_PATH", "")
+        hint = f"当前 ORACLE_CLIENT_PATH={client_path!r}" if client_path else "ORACLE_CLIENT_PATH 未设置"
+        raise RuntimeError(
+            f"Oracle Instant Client 未能加载（{hint}）。"
+            "请确认：① 已安装 Oracle Instant Client；"
+            "② 在系统环境变量中设置 ORACLE_CLIENT_PATH 指向 instantclient 目录；"
+            "③ 通过 PowerShell 重启后端服务以继承该环境变量。"
+        )
+
     user = quote_plus(username) if username else ""
     pwd = quote_plus(password) if password else ""
     if oracle_type == "sid":
-        # SID connections require connect_args in thin mode; work in both modes
         return create_engine(
             f"oracle+oracledb://{user}:{pwd}@",
             connect_args={"host": host, "port": int(port), "sid": database},

frontend/src/pages/DataSyncPage.tsx

@@ -115,6 +115,10 @@ function SyncTaskDialog({ open, onClose, onSaved, editSource, profiles, snack }:
   const [isActive, setIsActive] = useState(true)
   const [saving, setSaving] = useState(false)
 
+  // 步骤切换加载状态
+  const [stepping, setStepping] = useState(false)
+  const [steppingMsg, setSteppingMsg] = useState('')
+
   // 初始化
   useEffect(() => {
     if (!open) return
@@ -208,9 +212,23 @@ function SyncTaskDialog({ open, onClose, onSaved, editSource, profiles, snack }:
   const handleNext = async () => {
     if (step === 0) {
       if (!taskName.trim()) { snack.show('error', '请填写任务名称'); return }
-      if (profileId && tables.length === 0) await loadTables(profileId)
+      if (profileId && tables.length === 0) {
+        setStepping(true)
+        setSteppingMsg('正在连接数据库，获取数据表列表...')
+        try {
+          await loadTables(profileId)
+        } finally {
+          setStepping(false)
+          setSteppingMsg('')
+        }
+      }
     } else if (step === 1) {
       if (!previewDone && !editSource) { snack.show('error', '请先点击"预览数据"确认 SQL 可以正常执行'); return }
+      setStepping(true)
+      setSteppingMsg('正在分析字段结构，准备映射配置...')
+      await new Promise(r => setTimeout(r, 400))
+      setStepping(false)
+      setSteppingMsg('')
     }
     setStep(s => s + 1)
   }
@@ -281,7 +299,24 @@ function SyncTaskDialog({ open, onClose, onSaved, editSource, profiles, snack }:
         </Stepper>
       </Box>
 
-      <DialogContent dividers sx={{ minHeight: 400 }}>
+      <DialogContent dividers sx={{ minHeight: 400, position: 'relative' }}>
+
+        {/* ── 步骤切换加载覆盖层 ── */}
+        {stepping && (
+          <Box sx={{
+            position: 'absolute', inset: 0, zIndex: 10,
+            display: 'flex', flexDirection: 'column',
+            alignItems: 'center', justifyContent: 'center',
+            bgcolor: 'rgba(255,255,255,0.85)',
+            backdropFilter: 'blur(2px)',
+            gap: 2,
+          }}>
+            <CircularProgress size={48} thickness={4} />
+            <Typography variant="body1" color="text.secondary" fontWeight={500}>
+              {steppingMsg}
+            </Typography>
+          </Box>
+        )}
 
         {/* ── Step 0: 基本设置 ── */}
         {step === 0 && (
@@ -383,7 +418,22 @@ function SyncTaskDialog({ open, onClose, onSaved, editSource, profiles, snack }:
 
             {/* 预览数据表格 */}
             <Grid item xs={12} md={7}>
-              {previewDone && columns.length > 0 ? (
+              {previewing ? (
+                <Box sx={{
+                  minHeight: 220, display: 'flex', flexDirection: 'column',
+                  alignItems: 'center', justifyContent: 'center', gap: 2,
+                  border: '1px solid', borderColor: 'primary.light',
+                  borderRadius: 2, bgcolor: 'primary.50',
+                }}>
+                  <CircularProgress size={40} thickness={4} />
+                  <Typography variant="body2" color="primary.main" fontWeight={500}>
+                    正在查询数据库，请稍候...
+                  </Typography>
+                  <Typography variant="caption" color="text.secondary">
+                    首次连接可能需要几秒钟建立网络通道
+                  </Typography>
+                </Box>
+              ) : previewDone && columns.length > 0 ? (
                 <Box>
                   <Typography variant="subtitle2" color="text.secondary" gutterBottom>数据预览</Typography>
                   <Box sx={{ overflow: 'auto', border: '1px solid', borderColor: 'divider', borderRadius: 1 }}>
@@ -525,14 +575,21 @@ function SyncTaskDialog({ open, onClose, onSaved, editSource, profiles, snack }:
       </DialogContent>
 
       <DialogActions sx={{ px: 3, py: 2, justifyContent: 'space-between' }}>
-        <Button onClick={step === 0 ? onClose : () => setStep(s => s - 1)} disabled={saving}>
+        <Button onClick={step === 0 ? onClose : () => setStep(s => s - 1)} disabled={saving || stepping}>
           {step === 0 ? '取消' : '上一步'}
         </Button>
         {step < WIZARD_STEPS.length - 1 ? (
-          <Button variant="contained" onClick={handleNext}>下一步</Button>
+          <Button
+            variant="contained"
+            onClick={handleNext}
+            disabled={stepping || previewing}
+            startIcon={stepping ? <CircularProgress size={16} color="inherit" /> : <ArrowForwardIcon />}
+          >
+            {stepping ? '加载中...' : '下一步'}
+          </Button>
         ) : (
           <Button variant="contained" onClick={handleSave} disabled={saving}
-            startIcon={saving ? <CircularProgress size={16} /> : undefined}>
+            startIcon={saving ? <CircularProgress size={16} color="inherit" /> : undefined}>
             {saving ? '保存中...' : (editSource ? '更新任务' : '创建任务')}
           </Button>
         )}