docs: add brand logos

.brand/README.md

@@ -0,0 +1,38 @@
+# Finch Brand Assets
+
+This directory contains official branding assets for Finch.
+
+## Files
+
+| File | Description |
+|------|-------------|
+| `finch-logo-horizontal.svg` | Full horizontal logo — bird mark + wordmark, light mode |
+| `finch-logo-horizontal-dark.svg` | Full horizontal logo — bird mark + wordmark, dark mode |
+| `finch-icon-circle.svg` | Bird mark inside a circle, light mode |
+| `finch-icon-circle-dark.svg` | Bird mark inside a circle, dark mode |
+
+## Colours
+
+| Role | Hex |
+|------|-----|
+| Brand navy | `#20415a` |
+| White | `#ffffff` |
+
+## Usage
+
+- Use the **light** variants on white or light-coloured backgrounds.
+- Use the **dark** variants on dark backgrounds (e.g. GitHub dark theme).
+- For GitHub `README.md` use a `<picture>` element to switch automatically:
+
+```html
+<picture>
+  <source media="(prefers-color-scheme: dark)" srcset=".brand/finch-logo-horizontal-dark.svg">
+  <img src=".brand/finch-logo-horizontal.svg" alt="Finch - The Minimal Observability Infrastructure" width="300">
+</picture>
+```
+
+## Notes
+
+- All assets have a transparent background unless otherwise noted
+  (`finch-icon-circle.svg` has a white fill inside the circle stroke).
+- Do not alter the wordmark paths or the proportions of the bird mark.

README.md

@@ -1,4 +1,9 @@
-# The Minimal Observability Infrastructure 
+<picture>
+  <source media="(prefers-color-scheme: dark)" srcset=".brand/finch-logo-horizontal-dark.svg">
+  <img src=".brand/finch-logo-horizontal.svg" alt="Finch - The Minimal Observability Infrastructure" width="300">
+</picture>
+
+# The Minimal Observability Infrastructure
 
 [![Tag](https://img.shields.io/github/tag/tschaefer/finch.svg)](https://github.com/tschaefer/finch/releases)
 [![Go Report Card](https://goreportcard.com/badge/github.com/tschaefer/finch)](https://goreportcard.com/report/github.com/tschaefer/finch)