fix: semanticEnable not applied to title and description text

[Copilot]

Description

The semanticEnable flag was not propagated from ShowcaseView to the actual text widgets, leaving title and description text unexposed to screen readers. This particularly affected apps using go_router with nested navigation where the overlay semantics tree is separate from the route's context.

Changes

Flow Fix: Thread semanticEnable through widget tree

• ToolTipWrapper → ToolTipContent → DefaultTooltipTextWidget

Semantic Wrapper: DefaultTooltipTextWidget

• Added semanticEnable and isHeader parameters
• Wraps text with Semantics(label, header, liveRegion) when enabled
• Title marked as header for proper semantic hierarchy

Parameter Passing: ToolTipContent

• Accepts semanticEnable, passes to title (isHeader: true) and description (isHeader: false)

Usage

ShowcaseView.register(
  semanticEnable: true,  // Now properly applied to text
  // ...
);

Checklist

• The title of my PR starts with a Conventional Commit prefix (fix:, feat:, docs: etc).
• I have followed the Contributor Guide when preparing my PR.
• I have updated/added tests for ALL new/updated/fixed functionality.
• I have updated/added relevant documentation in docs and added dartdoc comments with ///.
• I have updated/added relevant examples in examples or docs.

Breaking Change?

• Yes, this PR is a breaking change.
• No, this PR is not a breaking change.

Original prompt

---

This section details on the original issue you should resolve

<issue_title>new option "semanticEnable" don't work (title and description)</issue_title>
<issue_description>Describe the bug
using the latest version (master) with semanticEnable: true. the semantics on Showcase (title and description) don't work

</issue_description>

<agent_instructions>Please investigate why Flutter semantics are not working when using go_router.

The accessibility feature was implemented in this PR:
#604

However, when the app is using go_router (especially with nested navigation or ShellRoute), the semantics/live region updates are not being announced or exposed correctly in the semantics tree.

Kindly analyze the routing layer and identify why semantics are being blocked or lost, and suggest a fix or workaround.</agent_instructions>

Comments on the Issue (you are @copilot in this section)

@Sahil-Simform Hi @etmyhome, could you please share a minimal reproducible code example? That will help us pinpoint the issue.

• Fixes new option "semanticEnable" don't work (title and description) #622

---

✨ Let Copilot coding agent set things up for you — coding agent works faster and does higher quality work when set up for your repo.