fix: [UIE-9816] - Empty state does not display correctly when category filter is selected first

[pmakode-akamai]

Description 📝

Previously, when a category filter was selected first, the UI would show a blank screen instead of the "No results found" empty state.

This edge case happened because filteredProducts still contained products from other categories, even though the selectedCategory itself had zero products. As a result, the empty state logic was never triggered.

This PR fixes the issue by including the selectedCategory in the initial filtering process (when a category is already selected). This ensures filteredProducts accurately reflects the selected category and correctly displays the empty state when no results are available.

NOTE: A changeset may not be necessary for this fix since the main PR has not been released yet.

Changes 🔄

• Updated the product filtering logic to include selectedCategory during initial filter processing.
• Ensured the empty state is displayed when the selected category contains no products.
• Prevented blank screen scenarios when a category filter is applied first.
• Add more unit tests

Scope 🚢

Upon production release, changes in this PR will be visible to:

• All customers
• Some customers (e.g. in Beta or Limited Availability)
• No customers / Not applicable

Target release date 🗓️

N/A

Preview 📷

Before (on develop branch)	After (on this branch)

How to test 🧪

Prerequisites

• Enable Marketplace v2 feature flag

Reproduction steps

1. Navigate to Partner Referrals landing page
2. Select "Networking" category
3. Type "4" into the search field
4. ⛔️ Observe a blank page
5. Select either "SaaS & APIs" or "Agentic Systems" type
6. ℹ️ Observe that the "No results found" message appears
7. Select "Data Service" type
8. ⛔️ Observe the "No results found" message disappears and a blank page is shown again

Verification steps

• Follow the reproduction steps and verify that no blank screen is displayed at any point
  • Verify that when searching for product details that do not belong to the selected category, the "No results found" empty state is displayed instead of a blank screen
• Ensure all filtering scenarios work as expected
• Ensure all tests pass

Author Checklists

As an Author, to speed up the review process, I considered 🤔

👀 Doing a self review
❔ Our contribution guidelines
🤏 Splitting feature into small PRs
➕ Adding a changeset
🧪 Providing/improving test coverage
🔐 Removing all sensitive information from the code and PR description
🚩 Using a feature flag to protect the release
👣 Providing comprehensive reproduction steps
📑 Providing or updating our documentation
🕛 Scheduling a pair reviewing session
📱 Providing mobile support
♿ Providing accessibility support

• I have read and considered all applicable items listed above.

As an Author, before moving this PR from Draft to Open, I confirmed ✅

• All tests and CI checks are passing
• TypeScript compilation succeeded without errors
• Code passes all linting rules

[linode-gh-bot]

Cloud Manager UI test results

🔺 1 failing test on test run #2 ↗︎

❌ Failing	✅ Passing	↪️ Skipped	🕐 Duration
1 Failing	864 Passing	11 Skipped	40m 43s

Details

Failing Tests
	Spec	Test
❌	clone-linode.spec.ts	Cloud Manager Cypress Tests→clone linode » can clone a Linode from Linode details page

Troubleshooting

Use this command to re-run the failing tests:

pnpm cy:run -s "cypress/e2e/core/linodes/clone-linode.spec.ts"