Test: Customization Marketplace Discover gating and source composition

[pwang347]

Refs: #333757, #336202
PRs: #337110, #337810, #337574, #337577

• anyOS Kyle Cutler (@kycutler)
• anyOS Christof Marti (@chrmarti)

Complexity: 4

Authors: Paul (@pwang347)

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Context

Agent Customizations now has a unified Discover surface. Marketplace visibility is gated independently from its sources, and Discover composes the GitHub Feed, MCP Gallery, and configured Plugin marketplaces without duplicating the default public catalogs.

Use a disposable profile. No custom registry is required for the core test.

Baseline and visibility gate

1. Remove any explicit values for these settings, then set only chat.customizations.marketplace.enabled to false:
   • chat.customizations.marketplace.enabled
   • chat.customizations.marketplace.sources.publicFeed.enabled
2. Run Chat: Open Customizations.
3. Verify the original Overview is shown. The MCP Servers and Plugins pages still contain their legacy Available sections, and no Discover content appears even though the GitHub Feed defaults on.
4. Set chat.customizations.marketplace.enabled to true.
5. Verify Discover replaces Overview and the home action is named Discover.
6. Start a search, then turn Marketplace off before it completes. Verify Overview returns, stale results do not appear, and the legacy MCP/Plugin catalogs remain usable.
7. Turn Marketplace back on and verify a fresh Discover query starts.

Source composition and de-duplication

1. Set chat.customizations.marketplace.sources.publicFeed.enabled to false.
2. In Discover, verify the source picker offers MCP Gallery and Configured Plugin Marketplaces. Browse each source and verify its default catalog loads.
3. Verify discovery has moved out of the MCP Servers and Plugins management pages while Marketplace is visible; installed-item management remains there.
4. Re-enable chat.customizations.marketplace.sources.publicFeed.enabled.
5. Verify GitHub Feed appears without reloading the window. Search for a public item that is also present in a default MCP or Plugin catalog and verify it is not duplicated across sources. Custom/workspace Plugin marketplaces, if configured, should remain available.
6. Scope the source picker to each source and then return to all sources. Verify the visible results and source label update each time.

Search, paging, failure isolation, and accessibility

1. Search across multiple customization types. Exercise the type and installed filters, clear the search, and verify Featured content returns.
2. Scroll through enough results to load another page. Results already loaded should remain stable and equal-priority sources should stay interleaved rather than one source monopolizing the page.
3. Disable one source while a query is running. Verify healthy sources remain visible and retrying/re-enabling restarts that source from its first page.
4. Navigate Discover, its filters, source picker, cards, and list using only the keyboard. Open Accessibility Help and Accessible View and verify source, type, installation state, and available actions are announced.
5. Restore the settings when done.

Expected: Marketplace visibility never leaks feed work into the original Overview; enabling it exposes one coherent Discover experience; the three source families compose without duplicate default content; and toggling, filtering, paging, partial failure, and accessible navigation remain predictable.

[chrmarti]

Not sure how to do "Start a search, then turn Marketplace off before it completes.".

[pwang347]

Not sure how to do "Start a search, then turn Marketplace off before it completes.".

Should be okay to ignore this one.

Regarding #338442, it should be possible to get more sources by configuring custom MCP or agent plugin registries