Upgrade Next.js and compatible dependencies

[austin-smith]

What Changed

• Upgrade both Next.js applications, @next/env, and eslint-config-next to 16.3.0.
• Migrate App Router error boundaries from unstable_retry to the stable retry API.
• Update compatible workspace dependencies, including Better Auth, Tailwind CSS, Radix UI, Lucide, Shiki, PgBoss, Redis, Turbo, Vitest, ESLint, Prettier, and Wrangler.
• Align the endpoint-forwarding worker and its test fixture with PgBoss 12.27's metadata-aware job types.
• Regenerate the pnpm lockfile and apply formatting required by Prettier 3.9.

Why

This adopts the supported Next.js 16.3 APIs, keeps the workspace current within its declared version ranges, and resolves compatibility and typing changes at their source. The dependency refresh also reduces the audit result from 23 advisories to one moderate advisory in Drizzle Kit's development-only dependency chain.

Validation

• pnpm install --frozen-lockfile
• pnpm outdated --compatible --recursive — no remaining compatible updates
• pnpm peers check
• pnpm verify — 26/26 tasks and 461 tests passed
• Production Next.js builds and route/authentication smoke tests
• Real PgBoss worker startup against PostgreSQL schema version 37 and clean shutdown
• git diff --check
• TruffleHog secret scan
• Automated pre-ship review — no findings
• Dependency audit — no high or critical advisories; one moderate development-tooling advisory remains