Tests Phase 3: TUI flow tests + remove ActiveHubProjects dead branch

[schneik80]

Summary

Final phase of the test-suite buildout. Phase 3 covers the L3 layer per the test plan: bubbletea state-machine transitions driven by direct Update(msg) calls, plus one cross-layer test that drives the full UI → tea.Cmd → api package → mocked APS server chain.

Also removes a dead branch in fusion.ActiveHubProjects flagged during Phase 2 review.

Coverage

Package	Phase 2	Phase 3	Δ
ui	24.5%	32.5%	+8pp
fusion	83.8%	84.2%	+0.4pp (from dead-code removal)
total	38.5%	43.1%	+4.6pp

Test additions (ui/app_test.go)

• TestUpdate_TokenReadyMsg_TransitionsToLoading / ..._EmptyTokenGoesAuthNeeded — auth state branching
• TestUpdate_KeyQuit — q in stateBrowsing returns tea.QuitMsg
• TestUpdate_NavigateRight_LoadsContents (cross-layer L2/L3) — drives a project NavigateRight through the ui state machine into the fan-out cmd that calls api.GetFolders + api.GetProjectItems concurrently against an httptest GraphQL fake; asserts the contentsLoadedMsg has folders before items and decodes into NavItems with the right Kind/IsContainer. End-to-end coverage of the most complex user action.
• TestVerifySameHub — 4 sub-cases (exact id match, name fallback when id unparseable, no match, empty-skips-check) against a fake MCP server
• TestRecoverFromError_AuthError_DeletesTokens — saves a token, triggers recovery from a "401 unauthorized" error, asserts state reset + tokens.json deleted from disk
• TestBreadcrumb_HitDetection — buildBreadcrumb produces 4 hits with right kinds, indices, monotonic x-bounds

Production changes

• api.SetGraphqlEndpointForTesting added so the ui flow test can swap the GraphQL endpoint without making the var itself exported. Doc explicitly says "production code MUST NOT call this".
• fusion.ActiveHubProjects dead branch removed (the payload.Success == false guard was unreachable — parseToolErrorText in callTool catches that case upstream and surfaces it via the err returned by c.invoke). TestActiveHubProjects_SuccessFalse tightened to assert the actual upstream error message ("tool reported failure") instead of accepting either branch as it did before.

Cumulative test-suite picture (3 phases)

Package	Final Coverage
config	90.6%
fusion	84.2%
auth	73.9%
api	69.7%
ui	32.5%
total	43.1%

Full go test -race -count=1 ./... runs in under 5s. CI workflow .github/workflows/test.yml (added in Phase 1) gates every PR.

Test plan

• make check passes locally
• TestUpdate_NavigateRight_LoadsContents confirmed to exercise the cross-layer chain (verified by inspecting captured GraphQL request bodies in the handler)
• TestRecoverFromError_AuthError_DeletesTokens confirmed to actually unlink the file (read it back returns (nil, nil))
• Confirm test workflow runs green on this PR

🤖 Generated with Claude Code