fix(TreeView): reset Items to null

[kimdiego2098]

修复 IsReset 为false时，Items变化后无法正常刷新 的问题

Summary of the changes (Less than 80 chars)

修复 IsReset 为false时，Items变化后无法正常刷新 的问题

Description

fixes #4895

Regression?

• Yes
• No

[If yes, specify the version the behavior has regressed from]

[是否影响老版本]

Risk

• High
• Medium
• Low

[Justify the selection above]

Verification

• Manual (required)
• Automated

Packaging changes reviewed?

• Yes
• No
• N/A

☑️ Self Check before Merge

⚠️ Please check all items below before review. ⚠️

• Doc is updated/provided or not needed
• Demo is updated/provided or not needed
• Merge the latest code from the main branch

Summary by Sourcery

Bug Fixes:

• Fix issue where TreeView does not refresh correctly when IsReset is false and Items change.

[sourcery-ai]

Reviewer's Guide by Sourcery

This PR fixes a TreeView refresh issue by adjusting when node recalculation occurs. The main change moves the _rows = null reset operation outside the IsReset condition, ensuring nodes are properly recalculated whenever Items change, regardless of the IsReset flag value.

No diagrams generated as the changes look simple and do not need a visual representation.

File-Level Changes

Change	Details	Files
Restructured node recalculation logic in TreeView component	Moved _rows nullification outside of IsReset condition block Ensures node recalculation happens for all Items changes Added comment indicating node recalculation purpose	src/BootstrapBlazor/Components/TreeView/TreeView.razor.cs

---

Tips and commands

Interacting with Sourcery

• Trigger a new review: Comment @sourcery-ai review on the pull request.
• Continue discussions: Reply directly to Sourcery's review comments.
• Generate a GitHub issue from a review comment: Ask Sourcery to create an
  issue from a review comment by replying to it.
• Generate a pull request title: Write @sourcery-ai anywhere in the pull
  request title to generate a title at any time.
• Generate a pull request summary: Write @sourcery-ai summary anywhere in
  the pull request body to generate a PR summary at any time. You can also use
  this command to specify where the summary should be inserted.

Customizing Your Experience

Access your dashboard to:

• Enable or disable review features such as the Sourcery-generated pull request
  summary, the reviewer's guide, and others.
• Change the review language.
• Add, remove or edit custom review instructions.
• Adjust other review settings.

Getting Help

• Contact our support team for questions or feedback.
• Visit our documentation for detailed guides and information.
• Keep in touch with the Sourcery team by following us on X/Twitter, LinkedIn or GitHub.

[bb-auto]

Thanks for your PR, @kimdiego2098. Someone from the team will get assigned to your PR shortly and we'll get it reviewed.

[sourcery-ai]

Hey @kimdiego2098 - I've reviewed your changes - here's some feedback:

Overall Comments:

• Please complete the PR template, especially the regression status and risk assessment sections.
• Consider adding a code comment explaining why _rows needs to be reset regardless of IsReset value.

Here's what I looked at during the review

• 🟢 General issues: all looks good
• 🟢 Security: all looks good
• 🟢 Testing: all looks good
• 🟢 Complexity: all looks good
• 🟢 Documentation: all looks good

---

Sourcery is free for open source - if you like our reviews please consider sharing them ✨

• X
• Mastodon
• LinkedIn
• Facebook

_{Help me be more useful! Please click 👍 or 👎 on each comment and I'll use the feedback to improve your reviews.}

[sourcery-ai]

Hey @kimdiego2098 - I've reviewed your changes - here's some feedback:

Overall Comments:

• Please complete the PR template with risk assessment, verification details, and other required information to help with review and maintenance.

Here's what I looked at during the review

• 🟢 General issues: all looks good
• 🟢 Security: all looks good
• 🟢 Testing: all looks good
• 🟢 Complexity: all looks good
• 🟢 Documentation: all looks good

---

Sourcery is free for open source - if you like our reviews please consider sharing them ✨

• X
• Mastodon
• LinkedIn
• Facebook

_{Help me be more useful! Please click 👍 or 👎 on each comment and I'll use the feedback to improve your reviews.}

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 100.00%. Comparing base (7de5f7e) to head (80e504b).
Report is 2 commits behind head on main.

Additional details and impacted files

@@            Coverage Diff            @@
##              main     #4894   +/-   ##
=========================================
  Coverage   100.00%   100.00%           
=========================================
  Files          623       624    +1     
  Lines        27846     27872   +26     
  Branches      3993      4003   +10     
=========================================
+ Hits         27846     27872   +26     

☔ View full report in Codecov by Sentry.
📢 Have feedback on the report? Share it here.