Add admin experimental condition analytics

[Spbd1]

Motivation

• Surface useful summaries for the new experimental conditions (revision access, reveal timing, memory distortion, cost visibility, explanation frame, replay) on the protected admin dashboard.
• Include the new experimental fields in the CSV export and ensure older submissions without those fields do not break exports or dashboard rendering.

Description

• Extended the server-side admin aggregation (lib/adminSubmissions.ts) by adding many new AdminStats fields and computing counts/averages/percentages for revision, delayed reveal, memory distortion, cost visibility, explanation frame, and replay-related metrics while ignoring missing legacy fields in averages.
• Added CSV export columns for all requested fields (e.g. revision_condition, attempted_pre_reveal_revision, used_revision_opportunity, revision_magnitude, reveal_timing_condition, stand_by_initial_interpretation, cost_visibility_condition, explanation_frame_condition, remembered_responsibility_error, remembered_constraint_suspicion_error, remembered_primary_attribution_matches_original, memory_distortion_magnitude, replay_completed, replay_assignment_condition, behavior_change_care_avoidance, etc.) and implemented a payloadColumn fallback so values from alternate (older) paths or missing fields export as blank instead of failing.
• Updated the admin UI (components/admin/AdminDashboard.tsx) to render compact tables/cards for the new experimental summaries via a new MetricSection component and experimentSections configuration, plus small formatting helpers (formatExperimentValue) to display counts, averages, and percentage values.
• Kept existing admin features (token-based stats fetch, JSON/CSV downloads, recent submissions table) intact and made the new stats tolerant of legacy submissions (blank/null outputs).

Testing

• Ran npm run typecheck and it completed successfully.
• Ran npm run lint and it completed successfully but with the pre-existing React Hook dependency warning in components/ParticipantBackgroundForm.tsx.
• Ran npm run build and the Next.js production build completed successfully (static pages generated and app compiled).

Files changed: lib/adminSubmissions.ts, components/admin/AdminDashboard.tsx.

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Codex Task