fix: resolve title size spec as ILayoutNumber

[g1f9]

🤔 This is a ...

• Bug fix
• TypeScript definition update

🔗 Related issue link

None — found while implementing an Office-compatible "title height ≤ 50% of the chart area" rule on top of VChart.

🔗 Related PR link

None.

🐞 Bugserver case id

N/A — no BugServer case; covered by unit tests.

💡 Background and solution

ITitleSpec inherits ILayoutItemSpec, and docs/assets/option/*/component/title.md pulls in common-layout-item, so the title's width / height / minWidth / maxWidth / minHeight / maxHeight are all documented as ILayoutNumber (number | ${number}% | (layoutRect) => number | {percent, offset}, percentages relative to the chart view rect). The component did not honor that contract.

1. The vertical fields were passed through untouched.

_getTitleAttrs had height: this._spec.height, minHeight: this._spec.minHeight, maxHeight: this._spec.maxHeight. vrender's Title.render uses them numerically (heightLimit: textStyle.height ?? maxHeight, and maxSubTextHeight = maxHeight - mainTextBoundsHeight), so a percent string or a callback is neither rejected nor applied — it just disappears. Measured on a 773×458 chart with a 12-line title:

spec	before	after
maxHeight: 60	heightLimit: 60 → 3 lines + ... ✅	unchanged
maxHeight: '50%'	heightLimit: '50%' → all 12 lines ❌	229 → clamped ✅
maxHeight: () => 72	heightLimit: undefined → all 12 lines ❌	72 → clamped ✅

{percent, offset} reached vrender as an object and made maxSubTextHeight NaN.

2. The horizontal fields were folded twice.

width / maxWidth did go through calcLayoutNumber, but against this.getLayoutRect() — the title's own rect, which LayoutItem.setAttrFromSpec + setRectInSpec have already clamped using the same value resolved against chartViewRect. On the same 773px-wide chart, maxWidth: '30%' resolved to 69.57px (= 0.3 × 0.3 × 773) instead of 231.9px. calcLayoutNumber was also called with callOp = null, so a callback got undefined instead of the documented ILayoutRect.

3. _getTitleLayoutRect read the raw spec, so a percent width was returned as a string and flowed into x2 = x + result.width.

Fix. A single _calcSpecSize(value, isHorizontal) helper resolves all six fields via calcLayoutNumber, using this._option.getChartViewRect() as both the percent base and the callback argument — exactly what layout-item.ts does for the same spec fields. _getTitleLayoutRect uses the resolved values too. The spec types are widened from number to ILayoutNumber to match.

The callback form is the one that really matters here: calcLayoutNumber re-evaluates it on every layout pass, so a rule that depends on the container ("title height ≤ 50% of the chart area") keeps holding across resize. A plain number measured once at spec-build time goes stale — and a percentage cannot express it either, because the title's own layoutRect.height is the title height, which makes it circular.

Scope / safety

• Numeric config is untouched: calcLayoutNumber returns numbers as-is, and the existing Math.min(titleWidth, titleMaxWidth, layoutRect.width) clamp is kept, so maxWidth still never exceeds the space the title actually got.
• Only percent / callback / {percent, offset} forms change behavior, and every one of them was previously either ignored or double-folded — there is no working behavior to preserve.
• Unset fields still resolve to undefined (not 0), so vrender's isValid(...) guards keep their current meaning.

Verified with the full packages/vchart/__tests__/unit suite: identical pass/fail set before and after, plus the 8 new title cases.

📝 Changelog

Language	Changelog
🇺🇸 English	Fix title width / height / minWidth / maxWidth / minHeight / maxHeight not being resolved as ILayoutNumber: percentages and callbacks on the vertical fields were silently ignored, and percentages on the horizontal fields were applied twice.
🇨🇳 Chinese	修复 title 的 width / height / minWidth / maxWidth / minHeight / maxHeight 未按 ILayoutNumber 解析的问题：纵向字段上的百分比与回调被静默忽略，横向字段上的百分比被折算了两次。

☑️ Self-Check before Merge

• Doc is updated/provided or not needed
• Demo is updated/provided or not needed
• TypeScript definition is updated/provided or not needed
• Changelog is provided or not needed

[xile611]

@g1f9 麻烦rebase 一下最新的develop提交一下，这样单测应该能通过了
文档部分，因为扩展了类型定义，需要说明一下版本号，下一个版本是 2.1.7

[xuefei1313]

🦞 Aime Bot Review

改动摘要

本 PR 修复 title 组件的 width / height / minWidth / maxWidth / minHeight / maxHeight 未按 ILayoutNumber 契约解析的问题：

• 新增 _calcSpecSize(value, isHorizontal) 统一收口，百分比基准与回调入参都使用 this._option.getChartViewRect()，与 layout-item.ts 对同名字段的处理保持一致；
• 纵向字段（height / minHeight / maxHeight）之前原样透传给 vrender，百分比/回调被静默忽略、{percent, offset} 对象形态会让 maxSubTextHeight 变成 NaN，现在都能正确解析；
• 横向字段（width / maxWidth）之前以 title 自身的 layoutRect 折算导致百分比被折两次、回调入参为 null，现在改为以图表视图区域解析且回调能拿到正确的 ILayoutRect；
• 类型定义从 number 放宽为 ILayoutNumber，中英文档同步更新，changelog（patch）齐备。

代码观察

1. 整体思路清晰：六个字段统一走 _calcSpecSize，isNil 守卫保证未配置时仍返回 undefined（而非 0），vrender 侧 isValid(...) 的既有语义不受影响；数值配置原样返回，行为不变 👍。
2. maxWidth 的 clamp 用 titleWidth ?? layoutRect.width 替代旧的 defaultValue 传参，数值场景下与旧逻辑等价；maxWidth: '90%' → 被 layoutRect 钳制的用例也验证了「不超过实际分配空间」这一约束仍然成立。
3. 有一点请确认：attrs 中新增了 width: titleWidth（旧代码只传 maxWidth，不传 width）。数值 width 场景下旧逻辑也会通过 Math.min(titleWidth, ...) 收敛到 maxWidth，预期表现一致；但请确认 vrender 的 Title 组件在显式收到 width 时，文字换行/布局表现与仅传 maxWidth 时一致（未配置时为 undefined，无影响）。
4. 小建议（非阻塞）：_getTitleAttrs 中 6 个字段各自调用一次 _calcSpecSize，每次都会调 this._option.getChartViewRect()；可以在方法内缓存一次 chartViewRect 复用，既省几次调用，也能保证同一次布局解析内基准完全一致。
5. 测试方面：新增 8 个用例覆盖百分比、回调、数值、未配置以及 clamp，覆盖合理 👍。另外 PR 描述提到 {percent, offset} 对象形态之前会导致 NaN，但单测里没有该形态的用例，建议补一个（如 { percent: 0.5, offset: 10 }）的断言，把这个回归也锁死。
6. 文档与 changelog 流程规范，ITitleSpec 的 JSDoc 也同步说明了百分比/回调的基准是图表视图区域。

合并建议

修复方向正确、测试与文档齐备，建议在 CI 通过、并确认上面第 3 点（width 显式透传的渲染表现）后合并 ✅。第 4、5 点为非阻塞建议，可在本 PR 或后续跟进。