[Lint 04] fix: burn down frontend eslint errors; make CI lint blocking

[amal66]

Summary

Follow-up to #232: burns the frontend eslint error backlog down from 23 errors / 40 warnings to 0 errors / 40 warnings, then flips the CI lint step from advisory (continue-on-error: true) to a blocking gate. All edits are minimal and behavior-preserving — no rule is disabled repo-wide.

Stacking note: this branch stacks on #232 and includes its ci.yml commit — please review the top commit only (fix: burn down frontend eslint errors; make CI lint blocking). Will be Graphite-stacked properly once write access allows.

Changes

Rule	Count	How it was resolved
@typescript-eslint/no-explicit-any	5	Fixed. ChatView.tsx used (msg as any).files / .workflow / .error, but the Message interface (shared/types.ts) already declares all three fields with exactly the shapes the UserMessage / AssistantMessage props expect. Casts removed; plain property access type-checks cleanly (verified by next build, which runs tsc).
react/no-unescaped-entities	1	Fixed. support/page.tsx: We'll → We'll.
react-hooks/set-state-in-effect	17	Targeted // eslint-disable-next-line with a one-line reason at each site (details below). Every occurrence is an intentional effect-driven state pattern; any "real" fix (derive-during-render, key-based remount, useSyncExternalStore) would change runtime behavior, so per-site disables were the safe call.

The 17 set-state-in-effect disables and their reasons

Site	Reason
modals/Modal.tsx:64	SSR portal gate — hasMounted must flip after first client mount
hooks/useSelectedModel.ts:19	Hydration-safe localStorage read; SSR must render the default model
hooks/useFetchDocxBytes.ts:52	Clear stale bytes when documentId is removed, inside the fetch effect
contexts/ChatHistoryContext.tsx:76	Clear chat state on logout inside the effect that loads chats
assistant/CaseLawPanel.tsx:219	Sync path of an async fetch effect: serve prop/cache data without a loading flash
assistant/CaseLawPanel.tsx:272	Reset active opinion after opinions load
assistant/CaseLawPanel.tsx:276	Sync quote list when the tab prop changes
assistant/CaseLawPanel.tsx:324	Reset quote selection when the quote set changes
assistant/ChatView.tsx:86	Reset per-chat UI state when switching chats
assistant/ChatView.tsx:522	Initial scroll-button state must be measured from the live DOM
assistant/ChatView.tsx:556	Hide messages until scroll position is restored to avoid a visible jump
assistant/CitationQuotesHeader.tsx:50	Collapse list view when quotes drop to a single item
assistant/PreResponseWrapper.tsx:32	Streaming open/minimize latch (existing comment documents why)
assistant/AskInputPopup.tsx:245	Auto-submit when every question is answered; submit() sets state as part of the side effect
shared/MfaLoginGate.tsx:24	Sync fast paths of the async MFA check effect
shared/MfaLoginGate.tsx:67	Clear gate when a recent MFA verification exists instead of redirecting
tabular/TRChatPanel.tsx:167	Timed "Done" flash on the active→idle transition

CI

.github/workflows/ci.yml: removed continue-on-error: true from the frontend lint step and rewrote the step comment (and the header note) — lint is now a blocking gate since the error backlog is at zero. Warnings do not fail the step.

Why

#232 landed the lint step as advisory-only because main carried 23 inherited eslint errors and a blocking gate would have turned every PR red on debt it didn't create. With the backlog at zero, the gate can hold the line: any new eslint error fails CI at the PR, instead of accreting silently.

Testing

• cd frontend && npm run lint — exits 0: 0 errors, 40 warnings (was 23 errors / 40 warnings; warnings are pre-existing, mostly no-unused-vars on node ref params and no-explicit-any warnings in test-adjacent code).
• npm test — no test script exists on this branch (predates the vitest harness PR); CI's npm test --if-present no-ops, as designed in [CI 03] ci: build and test workflow for backend and frontend #232.
• NEXT_PUBLIC_SUPABASE_URL=https://placeholder.supabase.co NEXT_PUBLIC_SUPABASE_PUBLISHABLE_DEFAULT_KEY=sb_publishable_placeholder NEXT_PUBLIC_API_BASE_URL=http://localhost:3001 npm run build — passes (compiles + type-checks all routes), confirming the ChatView.tsx cast removals are type-safe.

🤖 Generated with Claude Code

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