feat: initial Tatsumi release

Tatsumi is a Tauri desktop app for generating AI character art of Naomi
using Google Gemini's image model. Features three generation modes
(avatar, art, replace), persistent conversation threads, message
editing and deletion, retry support, cost tracking, and an about modal
with lore-accurate self-introduction from Emi Carrigan.

README.md

@@ -1,20 +1,44 @@
-# New Repository Template
+# Tatsumi
 
-This template contains all of our basic files for a new GitHub repository. There is also a handy workflow that will create an issue on a new repository made from this template, with a checklist for the steps we usually take in setting up a new repository.
+Tatsumi is a desktop app for generating AI character art powered by Google Gemini's image model. It's built specifically to generate art of Naomi, with her reference sheet pre-loaded so you just describe the scene.
 
-If you're starting a Node.JS project with TypeScript, we have a [specific template](https://github.com/naomi-lgbt/nodejs-typescript-template) for that purpose.
+## Features
 
-## Readme
+### Three generation modes
 
-Delete all of the above text (including this line), and uncomment the below text to use our standard readme template.
+- **Avatar** — Generate a portrait or avatar from a text prompt (1:1 aspect ratio)
+- **Art** — Generate a full widescreen piece from a text prompt (16:9 aspect ratio)
+- **Replace** — Upload a source image and describe what you want changed or reimagined
 
-<!-- # Project Name
+### Conversation threads
 
-Project Description
+Each generation session is a thread. You can send follow-up messages to refine the result, retry any response, edit a previous prompt and re-run, or delete messages. Threads are saved locally and persist between sessions.
 
-## Live Version
+### Other bits
 
-This page is currently deployed. [View the live website.]
+- Model reasoning is shown as a collapsible "Model reasoning" section on each response
+- Cost per response is displayed (input + output tokens)
+- Generated images can be downloaded directly from the chat
+- App version shown in the sidebar header
+
+## Setup
+
+You'll need a [Google Gemini API key](https://aistudio.google.com/apikey) to use Tatsumi. On first launch, you'll be prompted to enter it. You can update it any time via Settings.
+
+## Running locally
+
+```bash
+pnpm install
+pnpm tauri dev
+```
+
+## Building
+
+```bash
+pnpm tauri build
+# or for Windows cross-compilation:
+pnpm build:windows
+```
 
 ## Feedback and Bugs
 
@@ -36,4 +60,4 @@ Copyright held by Naomi Carrigan.
 
 ## Contact
 
-We may be contacted through our [Chat Server](http://chat.nhcarrigan.com) or via email at `contact@nhcarrigan.com`. -->
+We may be contacted through our [Chat Server](https://chat.nhcarrigan.com) or via email at `contact@nhcarrigan.com`.