feat(steady): 完善稳态数据视图功能

- 更新纵坐标刻度算法，优化小数趋势图范围显示
- 添加稳态趋势图全屏模式和共享工具组件
- 实现多图联动的鼠标悬停竖线同步功能
- 调整主线线宽分档策略，降低最大线宽限制
- 重构稳态趋势工具栏，优化谐波次数选择逻辑
- 添加周时间周期搜索支持和自定义时间范围选择
- 完善稳态数据表格和指示器浮动面板功能
- 优化稳态趋势图性能，添加LTB采样和动画控制
- 修复数据表格打开前的趋势数据验证问题
- 统一时间轴标签格式化和网格对齐处理

frontend/src/views/steady/steadyTrend/contracts/check-selection-contract.mjs

@@ -0,0 +1,73 @@
+/* eslint-env node */
+import fs from 'node:fs'
+import path from 'node:path'
+import { fileURLToPath } from 'node:url'
+
+const currentDir = path.dirname(fileURLToPath(import.meta.url))
+const componentDir = path.join(currentDir, '..', 'components')
+
+const read = file => fs.readFileSync(path.join(componentDir, file), 'utf8')
+const pageSource = fs.readFileSync(path.join(currentDir, '..', 'index.vue'), 'utf8')
+const selectionRulesSource = fs.readFileSync(path.join(currentDir, '..', 'utils', 'selectionRules.ts'), 'utf8')
+
+const expectations = [
+    [
+        'ledger tree excludes half-checked parents when collecting checked nodes',
+        /getCheckedNodes\(\s*false\s*,\s*false\s*\)/,
+        read('SteadyLedgerTree.vue')
+    ],
+    [
+        'indicator tree excludes half-checked parents when collecting checked nodes',
+        /getCheckedNodes\(\s*false\s*,\s*false\s*\)/,
+        read('SteadyIndicatorTree.vue')
+    ],
+    [
+        'selection rules expose the first selectable ledger resolver',
+        /export const findFirstSelectableLedgerNode/,
+        selectionRulesSource
+    ],
+    [
+        'selection rules expose the first leaf indicator resolver',
+        /export const findFirstLeafIndicator/,
+        selectionRulesSource
+    ],
+    [
+        'steady page applies default selected ledger keys after ledger tree load',
+        /defaultLedgerCheckedKeys\.value\s*=/,
+        pageSource
+    ],
+    [
+        'steady page applies default selected indicator keys after indicator tree load',
+        /defaultIndicatorCheckedKeys\.value\s*=/,
+        pageSource
+    ],
+    ['ledger tree receives default checked keys', /defaultCheckedKeys/, read('SteadyLedgerTree.vue')],
+    [
+        'ledger tree renders level icons',
+        /<component\s+:is="resolveLedgerIcon\(data\.level\)"/,
+        read('SteadyLedgerTree.vue')
+    ],
+    [
+        'ledger tree resolves icons by ledger level',
+        /const\s+ledgerIcons[\s\S]*0:[\s\S]*1:[\s\S]*2:[\s\S]*3:/,
+        read('SteadyLedgerTree.vue')
+    ],
+    ['indicator tree receives default checked keys', /defaultCheckedKeys/, read('SteadyIndicatorTree.vue')],
+    [
+        'selection rules dedupe leaf indicators collected from checked parents and children',
+        /seenIndicatorKeys[\s\S]*node\.indicatorCode[\s\S]*seenIndicatorKeys\.has[\s\S]*seenIndicatorKeys\.add/,
+        selectionRulesSource
+    ]
+]
+
+const failures = expectations.filter(([, pattern, source]) => !pattern.test(source))
+
+if (failures.length) {
+    console.error('steadyTrend selection contract failed:')
+    for (const [name] of failures) {
+        console.error(`- ${name}`)
+    }
+    process.exit(1)
+}
+
+console.log('steadyTrend selection contract passed')