fix: complete remaining 8 optimization items

- HTTP connection pooling: UpstreamClient & WebsiteClient reuse httpx.Client
- Deduplicate decimal_string into shared app/utils/number.py
- Split scheduler transaction: snapshot write → webhook/website sync in separate sessions
- Remove hardcoded 170.106.100.210 migration from database.py
- Reset consecutive_failures on upstream update
- Healthcheck: install curl, replace python -c with curl -f
- Add .dockerignore to reduce build context
- Frontend: add axios-retry with exponential backoff (5xx/network errors only)

frontend/package-lock.json

@@ -10,6 +10,7 @@
       "dependencies": {
         "@element-plus/icons-vue": "^2.3.1",
         "axios": "^1.7.9",
+        "axios-retry": "^4.5.0",
         "dayjs": "^1.11.13",
         "element-plus": "^2.8.8",
         "pinia": "^2.2.6",
@@ -1202,6 +1203,18 @@
         "proxy-from-env": "^2.1.0"
       }
     },
+    "node_modules/axios-retry": {
+      "version": "4.5.0",
+      "resolved": "https://registry.npmmirror.com/axios-retry/-/axios-retry-4.5.0.tgz",
+      "integrity": "sha512-aR99oXhpEDGo0UuAlYcn2iGRds30k366Zfa05XWScR9QaQD4JYiP3/1Qt1u7YlefUOK+cn0CcwoL1oefavQUlQ==",
+      "license": "Apache-2.0",
+      "dependencies": {
+        "is-retry-allowed": "^2.2.0"
+      },
+      "peerDependencies": {
+        "axios": "0.x || 1.x"
+      }
+    },
     "node_modules/balanced-match": {
       "version": "1.0.2",
       "resolved": "https://registry.npmmirror.com/balanced-match/-/balanced-match-1.0.2.tgz",
@@ -1593,6 +1606,18 @@
         "he": "bin/he"
       }
     },
+    "node_modules/is-retry-allowed": {
+      "version": "2.2.0",
+      "resolved": "https://registry.npmmirror.com/is-retry-allowed/-/is-retry-allowed-2.2.0.tgz",
+      "integrity": "sha512-XVm7LOeLpTW4jV19QSH38vkswxoLud8sQ57YwJVTPWdiaI9I8keEhGFpBlslyVsgdQy4Opg8QOLb8YRgsyZiQg==",
+      "license": "MIT",
+      "engines": {
+        "node": ">=10"
+      },
+      "funding": {
+        "url": "https://github.com/sponsors/sindresorhus"
+      }
+    },
     "node_modules/lodash": {
       "version": "4.18.1",
       "resolved": "https://registry.npmmirror.com/lodash/-/lodash-4.18.1.tgz",

frontend/package.json

@@ -8,13 +8,14 @@
     "preview": "vite preview"
   },
   "dependencies": {
-    "vue": "^3.5.13",
-    "vue-router": "^4.4.5",
-    "pinia": "^2.2.6",
-    "element-plus": "^2.8.8",
     "@element-plus/icons-vue": "^2.3.1",
     "axios": "^1.7.9",
-    "dayjs": "^1.11.13"
+    "axios-retry": "^4.5.0",
+    "dayjs": "^1.11.13",
+    "element-plus": "^2.8.8",
+    "pinia": "^2.2.6",
+    "vue": "^3.5.13",
+    "vue-router": "^4.4.5"
   },
   "devDependencies": {
     "@vitejs/plugin-vue": "^5.2.1",

frontend/src/api/index.ts

@@ -1,4 +1,5 @@
 import axios from 'axios'
+import axiosRetry from 'axios-retry'
 import router from '@/router'
 import { authStorageKeys } from '@/authStorage'
 
@@ -7,6 +8,19 @@ export const api = axios.create({
   timeout: 30000,
 })
 
+axiosRetry(api, {
+  retries: 3,
+  retryDelay: axiosRetry.exponentialDelay,
+  retryCondition: (err) => {
+    // Retry on network errors or 5xx, but never on 401/403/404/4xx
+    if (!err.response) return true
+    return err.response.status >= 500 && err.response.status < 600
+  },
+  onRetry: (_retryCount, _err, _requestConfig) => {
+    // no-op — could log in dev
+  },
+})
+
 api.interceptors.response.use(
   (r) => r,
   (err) => {