fix: Delete terms by their remote id and surface deletion failures

[dcalhoun]

Description

Fixes #23293. Fix CMM-2401.

Deleting a category over the wordpress-rs path failed with a 404 and left the confirmation dialog spinning on "Deleting category" forever. Two independent defects, both from #22252:

deleteTerm identified the term by its local database id. TermModel carries mId, the local @PrimaryKey row id, and mRemoteTermId, the id the API knows. deleteTerm sent term.id, so the API was asked to delete a term id belonging to something else and answered 404 rest_term_invalid. Every sibling already uses the remote identity — TaxonomyXMLRPCClient sends getRemoteTermId(), TaxonomyRestClient uses the slug, and updateTerm in the same class sends term.remoteTermId. Creating works because it needs no id. The success path had the mirror image of the slip, passing the local id as the confirmation model's remoteTermId.

A failed deletion was reported under a cause nothing subscribes to. A successful deletion emits OnTaxonomyChanged(causeOfChange = REMOVE_TERM); a failed one emitted DELETE_TERM. CategoryDetailViewModel, CategoriesListViewModel and SiteSettingsTagListActivity all match on REMOVE_TERM only, so the failure reached nobody and the InProgress state was never cleared. Both outcomes now emit REMOVE_TERM, and CategoryDetailViewModel already passes event.isError through to the message. This half affects every client — any failed term deletion left the dialog spinning, including on WordPress.com and XML-RPC sites.

Moving failures onto the cause every screen already listens to means the other two subscribers now receive an event they never saw before, so both had to be taught what to do with it:

• CategoriesListViewModel matched on the cause alone, so a rejected deletion triggered a refetch — the list posted Loading and, when the network was unavailable (a likely reason the deletion failed in the first place), replaced itself with the no-connection screen. It now refetches only on success.
• SiteSettingsTagListActivity shared one switch branch between REMOVE_TERM and UPDATE_TERM, which hides the progress dialog and pops the detail fragment unconditionally. A rejected tag deletion therefore closed the dialog and popped the screen with nothing but an AppLog line, indistinguishable from a success while the stale tag stayed in the list. It now shows a "Deleting tag failed" toast, matching the message the categories screen shows.

The existing delete tests stub WpApiClient.request wholesale, so the id sent was never observable and two assertions had been written against the wrong value. The new test runs the request against a stubbed executor and asserts the id itself. Every new test here was confirmed to fail without its fix.

Testing instructions

Note

The category deletion fix requires a site whose taxonomy requests go through wordpress-rs: added with an application password, with taxonomies_rest_api_migration enabled in the dev menu. The failure-reporting fixes apply to every site type.

Deleting a category:

1. Go to Site Settings → Categories and create a category.
2. Open the new category and delete it.

• Verify the category is deleted and disappears from the list
• Verify the DELETE request uses the same id the POST response returned (on trunk it uses a different one and returns 404)

Failed category deletion no longer hangs (regression check, reproducible on any site type):

1. With a proxy, fail DELETE */categories/* with a 500.
2. Delete a category.

• Verify the "Deleting category" spinner is replaced by "Failed to delete category" instead of spinning indefinitely
• Verify the category list behind it still shows the categories, rather than flashing a spinner or a "No connection" screen

Failed tag deletion reports the failure:

1. With a proxy, fail DELETE */tags/* with a 500.
2. Go to Site Settings → Tags, open a tag and delete it.

• Verify a "Deleting tag failed" toast appears rather than the screen closing silently

Regressions:

1. Create, rename and delete categories on a WordPress.com Simple site.

• Verify all three still work

2. Repeat on a self-hosted site with the feature flag disabled (XML-RPC path).

• Verify all three still work

3. Create, rename and delete tags.

• Verify all three still work, and that the list refreshes after each

🤖 Generated with Claude Code

https://claude.ai/code/session_011pj4FNhM3TFx83R5uDSuYh

[wpmobilebot]

📲 You can test the changes from this Pull Request in Jetpack Android by scanning the QR code below to install the corresponding build.

	App Name	Jetpack Android
	Build Type	Debug
	Version	pr23294-b8b8bd2
	Build Number	1498
	Application ID	com.jetpack.android.prealpha
	Commit	b8b8bd2
	Installation URL	4h6t0ajqa0ehg

Automatticians: You can use our internal self-serve MC tool to give yourself access to those builds if needed.

[wpmobilebot]

📲 You can test the changes from this Pull Request in WordPress Android by scanning the QR code below to install the corresponding build.

	App Name	WordPress Android
	Build Type	Debug
	Version	pr23294-b8b8bd2
	Build Number	1498
	Application ID	org.wordpress.android.prealpha
	Commit	b8b8bd2
	Installation URL	40pgvrilcn2io

Automatticians: You can use our internal self-serve MC tool to give yourself access to those builds if needed.

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 37.95%. Comparing base (b8157ff) to head (b8b8bd2).

Additional details and impacted files

@@            Coverage Diff             @@
##            trunk   #23294      +/-   ##
==========================================
+ Coverage   37.93%   37.95%   +0.01%     
==========================================
  Files        2352     2352              
  Lines      128925   128925              
  Branches    17940    17940              
==========================================
+ Hits        48907    48928      +21     
+ Misses      76012    75994      -18     
+ Partials     4006     4003       -3     

☔ View full report in Codecov by Harness.
📢 Have feedback on the report? Share it here.

🚀 New features to boost your workflow:

• ❄️ Test Analytics: Detect flaky tests, report on failures, and find test suite problems.
• 📦 JS Bundle Analysis: Save yourself from yourself by tracking and limiting bundle sizes in JS merges.