chore(harness): make repository agent-ready

Add concise routed context, task-aware agent roles, focused skills, and structured learning promotion.\n\nUnify local development and workspace tooling, add layered test and E2E verification, harden MCP authentication, and gate deployment behind verification and explicit production promotion.

apps/web/AGENTS.md

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+# Web application
+
+Next.js App Router marketing, legal, and redemption UI.
+
+- Prefer server components; add `use client` only when browser state is needed.
+- Preserve PostHog provider/page-view integration unless the task changes it.
+- Keep metadata current for public pages.
+- Never expose server credentials through `NEXT_PUBLIC_*` variables.
+- Public redemption must use sandbox/local Supabase during automated tests.
+- Verify lint, typecheck, build, and the relevant Playwright flow.