feat(local-explorer-ui): Add dark mode support

[NuroDev]

Fixes DEVX-2453.

While I am working on #12453 I have noticed that the data studio has already got dark mode support built in. As such it seemed better to get the basics of this done first.

Along with adding basic dark mode support, I added a number of little design refinements & style fixes:

• Added @cloudflare/kumo dependency to use the cn utility (Also to be migrated later on)
• Migrated all data property CSS styles into Tailwind CSS classes
• Fixed KV entry input placeholder text color
• Fixed "Add Entry" focus styles
• Fixed copy button hover grouping area
• Fixed KV input form responsive design
• Consolidated focus shadow styles into CSS variables
• Added edit & trash icon to entry action menu items
• Added link to / in sidebar header
• Replace breadcrumb > character with chevron icon
• Updated index page font styles + added Cloudflare logo
• Updated sidebar chevron icon to use Phosphor icons

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• Tests
  • Tests included/updated
  • Automated tests not possible - manual testing has been completed as follows: Visual style changes are currently not able to be tested due to no test suite being implemented. This will be implemented in the future.
  • Additional testing not necessary because:
• Public documentation
  • Cloudflare docs PR(s):
  • Documentation not necessary because: WIP Experimental feature

A picture of a cute animal (not mandatory, but encouraged)

[changeset-bot]

🦋 Changeset detected

Latest commit: a5750ad

The changes in this PR will be included in the next version bump.

Not sure what this means? Click here to learn what changesets are.

Click here if you're a maintainer who wants to add another changeset to this PR

[devin-ai-integration]

✅ Devin Review: No Issues Found

Devin Review analyzed this PR and found no potential bugs to report.

View in Devin Review to see 3 additional findings.

[pkg-pr-new]

create-cloudflare

npm i https://pkg.pr.new/create-cloudflare@12459

@cloudflare/kv-asset-handler

npm i https://pkg.pr.new/@cloudflare/kv-asset-handler@12459

miniflare

npm i https://pkg.pr.new/miniflare@12459

@cloudflare/pages-shared

npm i https://pkg.pr.new/@cloudflare/pages-shared@12459

@cloudflare/unenv-preset

npm i https://pkg.pr.new/@cloudflare/unenv-preset@12459

@cloudflare/vite-plugin

npm i https://pkg.pr.new/@cloudflare/vite-plugin@12459

@cloudflare/vitest-pool-workers

npm i https://pkg.pr.new/@cloudflare/vitest-pool-workers@12459

@cloudflare/workers-editor-shared

npm i https://pkg.pr.new/@cloudflare/workers-editor-shared@12459

@cloudflare/workers-utils

npm i https://pkg.pr.new/@cloudflare/workers-utils@12459

wrangler

npm i https://pkg.pr.new/wrangler@12459

commit: a5750ad

[devin-ai-integration]

Devin Review found 1 new potential issue.

View 6 additional findings in Devin Review.

[devin-ai-integration]

Devin Review found 1 new potential issue.

View 9 additional findings in Devin Review.

[petebacondarwin]

Despite being experimental, this PR does still need a changeset, I believe.
Also I don't think being experimental is a reason not to need tests. I think we should be ticking the "automated tests not possible" box and explaining that these are just styling changes and provide steps for how it has been (or can be) verified manually.

[petebacondarwin]

Playing around with it locally and all seemed good.

[devin-ai-integration]

Devin Review found 1 new potential issue.

View 10 additional findings in Devin Review.

[claude]

Claude finished @NuroDev's task —— View job

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Changeset Review

✅ All changesets look good

The changeset .changeset/dry-cooks-unite.md is well-formatted and follows the guidelines:

• Version type: minor is appropriate for adding dark mode support (new feature)
• Changelog quality: Clear description explaining what's being added and mentioning it uses system theme preference
• No markdown headers: ✅ No h1/h2/h3 headers used
• Experimental feature note: ✅ Includes "This is an experimental WIP feature"
• Package coverage: Correctly targets @cloudflare/local-explorer-ui

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Cuteness Report

This is... uh... well, it's the Cloudflare logo. Not exactly a pupper, but it does look cozy in that warm orange glow. The rounded edges give it a friendly vibe, like it's ready to handle your workers with a gentle embrace. Would give it a 7/10 for corporate mascot wholesomeness, but sadly can't rate as it's technically not an animal.

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