fix: silence duplicate error toasts in the digital-twin tabs (#2669)

[atomantic]

Summary

The Digital twin batch of the silent: true sweep. Refs #2669.

Most of this batch was already swept by #2682 — the issue's comments say so, and that held up. I re-verified rather than trusting them (the thread documents these lists going stale in both directions), using a wrapper-aware scan: classify every api* wrapper as toasting vs silent-by-default, then match custom-catch callers that don't pass silent. That plus review found four genuine bugs:

• OverviewTab — contradiction check. Renders the failure inline as contradictions.error, so request()'s default toast reported the same error a second time. Every sibling using the identical .catch(e => ({ error: e.message })) pattern (ConfidenceGauge, ListEnrichment, PersonalityMap, TestTab, EnrichTab, ImportTab) already passes silent — this was the outlier. Threaded a backward-compatible trailing options arg into detectDigitalTwinContradictions, the one affected wrapper.

• TasteTab — section reset. Toasted 'Section reset' unconditionally, so a failed reset stacked a success toast on top of request()'s error. Gated on the outcome via .then(() => true).catch(() => false), the form already used by PersonasTab:144 / TimeCapsuleTab:68. (Truthiness would be wrong — the endpoint 204s, so success is null.)

• TasteTab — "Go deeper" (found in review). Collapsed "request failed" and "nothing to ask" into the same null, so a failure got request()'s toast and a "try completing more identity documents" hint that misattributed the cause. Split with an undefined sentinel per CLAUDE.md's rule that failed-to-fetch must not collapse into legitimately-empty. No silent here — request() is the right single layer for the error, and the hint is now only reachable on the genuine 200-null path.

• OverviewTab — settings save (found in review). An uncaught rejection left saving true, stranding the Save button permanently disabled on "Saving..." with no retry. A state wedge rather than a toast bug, and adjacent to the sweep rather than part of it — rolled in because it's three lines in a file this batch already audits.

Known gap, deliberately not fixed here → #2733

Review flagged that "Go deeper"'s sentinel doesn't cover a provider failure, and that's correct: callProviderAISimple returns { error } instead of throwing (aiProvider.js:161,167,176), the service turns that into return null (taste-questionnaire.js:934-937), and the route bare-res.json()s it — so a provider error is 200-null, indistinguishable client-side.

I did not fix it here because the obvious fix is unsafe on its own: making the service throw would give request()'s toast plus useAIStatusNotifications' toast (it always toasts ai:status phase error, even for silent ops), re-creating the double toast #2669 exists to kill. It needs a server-side signal plus a decision about which layer owns the message — a server-contract change outside this client-side batch. Filed as #2733 with the full trace and acceptance criteria; the caveat is recorded at the call site.

Verified correct and deliberately left alone

• Toast-less swallowing catches (AccountsTab CRUD, PersonasTab, TimeCapsuleTab, TasteTab.handleGenerateSummary) — only a validation toast before the call or a toast.success on the happy path. These keep the single default layer; adding silent would remove their only failure feedback.
• Already passing silent — SoulWizard, NextActionBanner, AutobiographyTab (all 5), EnrichTab, ConfidenceGauge, ListEnrichment, PersonalityMap, ImportTab, ObservedTasteEvidence.
• TestTab:156 — catch has no toast, with a comment saying so. Correct single layer.
• The two grep-invisible classes prior batches flagged — no useAsyncAction / useLockToggle / useSseJobSlot consumers and no .then(onOk, onErr) sites in this directory.

Added client/src/services/apiDigitalTwin.test.js pinning that the wrapper forwards silent without clobbering method/body, and stays callable without options. This class of miss has recurred across batches, so it's worth a guard.

Test plan

• cd client && npx vitest run — 404 files / 4389 tests, 0 failures.
• New apiDigitalTwin.test.js covers silent-forwarding and the no-options back-compat path.
• Reviewers: claude (2 rounds — both findings applied) and codex --base origin/main (clean, no findings).
• Manual reasoning: a failed contradiction check shows only the inline red error; a failed Taste reset shows only request()'s error with no contradictory "Section reset"; a failed "Go deeper" no longer adds the misleading hint; a failed settings save re-enables the button.

Remaining

Batches still unswept on #2669 (counts unverified — re-scan first; every batch so far has found the advertised list stale):

• Creative Director (~3) — CreativeDirector.jsx:180, PlanTab.jsx:91/103/113, OverviewTab.jsx:148
• Catalog — CatalogCastPanel
• Meatspace
• Misc singles — GmailMboxImportPanel, LocalLlmTab, MessageDetail, GenomeTab, PipelineManuscriptEditor
• ManuscriptCommentCard.jsx:247,251 — generatePipelineManuscriptFix still needs an options param

Already shipped, do not re-sweep: settings + JIRA (#2670), messages/calendar/sharing, pipeline stages/canvas (#2714), writers-room/universe/universeBuilder/media/hooks (#2682), apps/GitHub/misc (#2721), LoRAs/media (#2723), and digital-twin (this PR — now exhausted apart from #2733).