feat: recast IdeaScape as an authorized bounty network - #13

Summary

• recasts IdeaScape as a focused authorized security-bounty network with explicit system-owner, reviewer, rules-of-engagement, and reproducible-proof boundaries
• preserves private reviewer signals and exposes creator evidence only as aggregate active-question totals
• adds migration reconciliation and transactional replay coverage that preserves unrelated private data and historical responses
• delivers distinct light/dark visual systems, professional shield/document iconography, descriptive media alternatives, and responsive catalog/detail workflows
• adds Playwright coverage for the focused home, mobile, catalog, and bounty-detail flows

Verification

• npm run check — 202 tests passed across 32 files; typecheck and Biome lint passed
• npm run format:check — passed
• npm run build — passed
• npm run test:e2e — 4 Playwright tests passed
• npx supabase db reset — all migrations applied from a clean database
• npx supabase test db — 244 pgTAP assertions passed
• npx supabase db lint --level warning — no schema errors
• psql ... -f supabase/verification/authorized-bounty-upgrade.test.sql — transactional migration replay and preservation probe passed
• responsive visual QA — desktop/mobile, dark/light, 390px viewport with no horizontal overflow or browser errors
• independent fail-closed review — approved after replacing the final prohibited death-metaphor icon

Security and privacy boundaries

• no authorization is inferred from a public listing or private readiness signal
• individual reviewer choices remain private and reversible
• system owners receive aggregate evidence only
• unrelated creator-owned records and historical response semantics are preserved