docs: add SEO descriptions to all doc pages and update hero subtitle

apps/docs/api/image-engine.md

@@ -1,3 +1,7 @@
+---
+description: Image engine operations reference. All Sharp-based image processing operations and their parameters.
+---
+
 # Image engine
 
 The `@snapotter/image-engine` package handles all non-AI image operations. It wraps [Sharp](https://sharp.pixelplumbing.com/) and runs entirely in-process with no external dependencies.

apps/docs/api/rest.md

@@ -1,3 +1,7 @@
+---
+description: Complete REST API reference. Tool endpoints, batch processing, pipelines, file library, authentication, teams, and admin operations.
+---
+
 # REST API Reference
 
 Interactive API docs with request/response examples are available at [http://localhost:1349/api/docs](http://localhost:1349/api/docs).

apps/docs/guide/configuration.md

@@ -1,3 +1,7 @@
+---
+description: All SnapOtter environment variables with defaults. Configure auth, storage, AI models, analytics, and more.
+---
+
 # Configuration
 
 All configuration is done through environment variables. Every variable has a sensible default, so SnapOtter works out of the box without setting any of them.

apps/docs/guide/contributing.md

@@ -1,3 +1,7 @@
+---
+description: How to contribute to SnapOtter. Bug reports, feature requests, and community guidelines.
+---
+
 # Contributing
 
 Thanks for your interest in SnapOtter. Community feedback helps shape the project, and there are several ways to get involved.

apps/docs/guide/database.md

@@ -1,3 +1,7 @@
+---
+description: SQLite database schema, tables, migrations, and backup procedures for SnapOtter.
+---
+
 # Database
 
 SnapOtter uses SQLite with [Drizzle ORM](https://orm.drizzle.team/) for data persistence. The schema is defined in `apps/api/src/db/schema.ts`.

apps/docs/guide/deployment.md

@@ -1,3 +1,7 @@
+---
+description: Deploy SnapOtter to production with Docker. Hardware requirements, GPU setup, and reverse proxy configs for Nginx, Traefik, and Cloudflare.
+---
+
 # Deployment
 
 SnapOtter ships as a single Docker container. The image supports **linux/amd64** (with NVIDIA CUDA) and **linux/arm64** (CPU), so it runs natively on Intel/AMD servers, Apple Silicon Macs, and ARM devices like the Raspberry Pi 4/5.

apps/docs/guide/developer.md

@@ -1,3 +1,7 @@
+---
+description: Local development setup, commands, code conventions, and how to add a new image processing tool to SnapOtter.
+---
+
 # Developer guide
 
 How to set up a local development environment and contribute code to SnapOtter.

apps/docs/guide/docker-tags.md

@@ -1,3 +1,7 @@
+---
+description: SnapOtter Docker image tags, GPU benchmarks, version pinning, and multi-platform support for AMD64 and ARM64.
+---
+
 # Docker Image
 
 SnapOtter ships as a single Docker image that works on all platforms.

apps/docs/guide/oidc.md

@@ -1,3 +1,7 @@
+---
+description: Set up Single Sign-On with OpenID Connect. Step-by-step guides for Keycloak, Authentik, Google, and other OIDC providers.
+---
+
 # OIDC / Single Sign-On
 
 SnapOtter supports OpenID Connect (OIDC) for single sign-on. Users can log in with an external identity provider such as Keycloak, Authentik, or Google instead of (or alongside) local username/password authentication.

apps/docs/guide/supported-formats.md

@@ -1,3 +1,7 @@
+---
+description: 55+ supported input formats including 23 camera RAW formats, and 14 output formats with full compatibility tables.
+---
+
 # Supported Image Formats
 
 SnapOtter supports 55+ image formats for input and 14 formats for output.

apps/docs/guide/translations.md

@@ -1,3 +1,7 @@
+---
+description: 21 supported languages and how to create or improve translations for SnapOtter using the TypeScript-enforced i18n system.
+---
+
 # Translation guide
 
 SnapOtter ships with 21 languages out of the box. The i18n system uses a lightweight custom runtime with TypeScript-enforced locale completeness and dynamic code-splitting.

apps/landing/src/components/hero.tsx

@@ -118,8 +118,8 @@ export function Hero() {
           Your images. Stay yours.
         </h1>
 
-        <p className="mt-4 animate-[fadeUp_0.6s_ease-out_0.1s_both] text-lg text-muted md:text-xl">
+        <p className="mt-4 animate-[fadeUp_0.6s_ease-out_0.1s_both] text-base text-muted md:text-lg">
-          Every image tool you need.
+          A free, open-source image editor with 52 tools that runs entirely on your device.
         </p>
 
         <p className="mt-4 animate-[fadeUp_0.6s_ease-out_0.2s_both] text-xl font-medium md:text-2xl">