Add Threads Contest Engine MVP monorepo

[ethgr0wth]

Motivation

• Provide a minimal but complete MVP monorepo implementing a contest engine with FastAPI+Redis backend and Next.js frontend to demo season/submission/judging/voting flows.
• Use Redis (DB 7) as the single source of truth with a strict key schema and TTL sessions for simple token auth and RBAC.
• Offer a usable UI (Tailwind + simple Aceternity-like styling) and an API client so the frontend can operate without local DB persistence.

Description

• Added backend FastAPI app under threadStax/backend/app with config.py, async redis_client.py, redis_keys.py (tc: prefix), Pydantic models in models.py, session auth in auth.py, RBAC dependency in rbac.py, and route modules implementing the required endpoints (auth, season(s), admin, submissions, judge, vote, leaderboard), plus requirements.txt and docker-compose.yml for Redis.
• Implemented the required Redis key schema and logic: user/session keys, seasons, submissions, moderation queue, judge assignments, per-judge scores, aggregated score pipeline updates, leaderboards, voting atomic pipeline, and simple rate-limits using INCR+TTL.
• Built a Next.js (App Router) TypeScript frontend under threadStax/frontend with pages and components matching the spec including landing, /login, /submit, judge/admin/voter pages, role-based RoleGate, Navbar, SeasonPicker, SubmissionCard, LeaderboardTable, moderation/judge queues, a typed lib/api.ts fetch wrapper, and lib/auth.ts storing token+uid+role in localStorage.
• Configured Tailwind, PostCSS, and basic dark/premium theme; documented quickstart instructions in README files at repository and per-package locations.

Testing

• Ran npm install in threadStax/frontend and the install completed successfully (packages added and audit reported warnings), which validates the frontend dependency graph installation.
• Ran npm run dev for the frontend which compiled the app successfully and served the site locally at http://localhost:3000 (Next.js compilation succeeded).
• Programmatically exercised the frontend using a Playwright script to load the homepage and capture a screenshot, which completed and produced an artifact confirming the UI renders.
• No backend integration tests were executed automatically in this run (backend assets and docker-compose are included for manual startup and testing).

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