Flaky backend tests: billing trial state, 3rd party broker topics, device APIs

[cstns]

While watching CI on open PRs we hit a batch of test failures that look unrelated to the PR under test (frontend-only change, PR #8467, run 34595722439). All 9 failed in the Postgres tests job and passed elsewhere, and the assertions look timing dependent.

• Billing routes > Can suspend/resume a trial project without touching billing (test/unit/forge/ee/routes/billing/index_spec.js:1453, expected undefined to be 'starting')
• 3rd Party Broker API > Verify topics all correct (test/unit/forge/ee/routes/teamBroker/3rdPartyBroker_spec.js:443)
• 3rd Party Broker API > Get Topics for 3rd Party broker as a Team Owner (3rdPartyBroker_spec.js:467)
• 3rd Party Broker API > Add Metadata to a Topic (3rdPartyBroker_spec.js:485)
• 3rd Party Broker API > Cannot add metadata to a topic for a broker in a different team (3rdPartyBroker_spec.js:516)
• 3rd Party Broker API > Delete Topic (3rdPartyBroker_spec.js:543)
• 3rd Party Broker API > Get Topics for team-broker as a Team Owner (3rdPartyBroker_spec.js:697, expected [] to have length 1)
• Device API > can unassign from a project (test/unit/forge/routes/api/device_spec.js:1358, null read)
• Project/Device API > returns a list of devices for team owner (test/unit/forge/routes/api/projectDevices_spec.js:168, expected [] to have length 1)

The broker topic tests failing as a block might share one root cause (broker state not settling before assertions). Might be worth starting there.

[cstns]

Another one from the same family, hit on PR #8467 (run 34836147852, Postgres tests job):

• Team Broker API > licensed > Test Topic listing by Team > Add topics to list (test/unit/forge/ee/routes/teamBroker/index_spec.js:1322, expected false to be true)

Same pattern as the other broker topic ones, an assertion on topic state right after adding topics. Re-ran the job.

[cstns]

One more, again on PR #8467 (run 34839432240, Postgres tests job):

• Project/Device API > Update project device settings > fails for unknown snapshot (test/unit/forge/routes/api/projectDevices_spec.js:200, expected 400 got 404)

Same spec file as the projectDevices_spec.js:168 entry above. Re-ran the job.

[cstns]

Two Cypress (UI EE) flakes this time, on PR #8502 (run 34854653678, UI EE tests job). Both in test/e2e/frontend/cypress/tests-ee/devices/developer-mode.spec.js, both a cy.click() timing out because a dialog overlay (ff-dialog-container--open) was still covering the tab link, each failed all 3 attempts:

• FlowFuse - Devices - With Billing > is redirected away from the Developer Mode tab if leaving that mode, whilst the tab is open
• FlowFuse - Devices - With Billing > has the option to "Create Snapshot" if owned by an Application

The PR only touches backend MCP tools, so unrelated. Looks like the dialog close animation racing the next click.

[cstns]

Another device API one, on PR #8503 (run 34854920756, Postgres tests job):

• Device API > Edit device details > edit device settings > cannot set targetSnapshot for snapshot outside of the team (test/unit/forge/routes/api/device_spec.js:1639, expected 400 got 200)

Third distinct flake in device_spec.js / projectDevices_spec.js territory, looks like shared fixture state leaking between tests. Re-ran the job.