Fix Slider property update freezing UI

[hannahblair]

Summary

• Fixes UI freeze when updating Slider properties (visibility, range) via button callbacks (Slider property update freezes UI in Gradio ≥6.6.0 (works in 6.5.1) #12995)
• Removed redundant range_input.value direct DOM write that conflicted with Svelte's bind:value, causing value clamping against stale min/max and triggering infinite update loops
• Made range_input reactive ($state) so the CSS progress effect re-runs when the element becomes available after visibility toggle
• Used untrack for old_value write in change detection effect to prevent unnecessary re-runs
• Reordered min/max attributes before bind:value on the range input to prevent browser clamping

Test plan

• Existing slider unit tests pass (Slider.test.ts - 2/2)
• Verify with reproduction script (Variant 1 - gr.update(visible=True))
• Verify with reproduction script (Variant 2 - gr.Slider(...) constructor)
• Confirm slider CSS progress bar renders correctly after visibility toggle
• Confirm change events still fire correctly (including value=0)

Closes #12995

🤖 Generated with Claude Code

[gradio-pr-bot]

🪼 branch checks and previews

•	Name	Status	URL
	Spaces	ready!	Spaces preview
	Storybook	failed!	Details
🦄	Changes	detected!	Details

---

Install Gradio from this PR

pip install https://gradio-pypi-previews.s3.amazonaws.com/546f26af7f35634ac424821d2e8a85a2f99b9739/gradio-6.9.0-py3-none-any.whl

Install Gradio Python Client from this PR

pip install "gradio-client @ git+https://github.com/gradio-app/gradio@546f26af7f35634ac424821d2e8a85a2f99b9739#subdirectory=client/python"

Install Gradio JS Client from this PR

npm install https://gradio-npm-previews.s3.amazonaws.com/546f26af7f35634ac424821d2e8a85a2f99b9739/gradio-client-2.1.0.tgz

[gradio-pr-bot]

🦄 change detected

This Pull Request includes changes to the following packages.

Package	Version
@gradio/slider	patch
gradio	patch

---

• Fix Slider property update freezing UI

---

‼️ Changeset not approved. Ensure the version bump is appropriate for all packages before approving.

• Maintainers can approve the changeset by checking this checkbox.

Something isn't right?

• Maintainers can change the version label to modify the version bump.
• If the bot has failed to detect any changes, or if this pull request needs to update multiple packages to different versions or requires a more comprehensive changelog entry, maintainers can update the changelog file directly.

[hannahblair]

testing kumquat but forgot to update branch