Full-Stack Developer Needed for Viral AI Web App

I am seeking a full-stack developer to build a mobile-first, conversion-optimized single-page web app called the "Global Time-Travel Costume Studio." The app allows casual users to upload 1 clear selfie, interact with a simple 5-field menu framework, and instantly generate an ultra-realistic, identity-preserving historical portrait of themselves. Key Architecture Rules (Strictly Defined in Attached Scope): Zero User Friction: No user accounts, login screens, or profile creation. It is a straight, frictionless interaction loop. 5 Selection Fields: 4 simple dropdown arrays (with Field 2 dynamically updating using a backend text LLM API timeline from ancient eras to modern day) and 1 optional custom text entry box. Pre-Built Banner Spaces: Code must natively include placeholder blocks for a Top Horizontal Leaderboard Banner and a Desktop Side Skyscraper Banner. Backend AI APIs: Direct connection to endpoints like Fal.ai or Replicate using identity-retaining image pipelines (such as InstantID) set to randomized seeds. Automatic 4K Upscaler: The download function must trigger a post-processing upscaler to provide studio-print-ready 4K files. Ephemeral Storage: An automatic 24-hour file-wipe worker to maintain zero long-term data footprint. Payment Layer: Stripe sub-account integration configured exclusively for Stripe's Micropayments fee tier ($0.99 single unlock / $2.99 5-image bundle). Full Scope Attached: I have attached the finalized, complete Statement of Work (SOW) V2 covering every milestone, interface field, ad banner slot, and pipeline block. This document represents the total and complete scope of this fixed-price contract. No out-of-scope price alterations will be accepted post-hire. Please review the document, share relevant examples of your past AI image/Stripe webhook integrations, and provide your fixed-price budget and delivery timeline estimates.