refactor: split git provider adapters

README.md

@@ -12,7 +12,7 @@ Built for La Fabrik Durable's internal use, but open-sourced for anyone looking
 - [**Next.js 16.2.5** (App Router)](https://nextjs.org/docs/app/getting-started/installation) + [React 19](https://react.dev/learn/creating-a-react-app) + [TypeScript](https://www.typescriptlang.org/docs/)
 - [**Three.js**](https://threejs.org/docs/#manual/en/introduction/Creating-a-scene) ([React Three Fiber](https://r3f.docs.pmnd.rs/getting-started/introduction) + [Drei](https://drei.docs.pmnd.rs/getting-started/introduction)) for 3D preview
 - [**Tailwind CSS**](https://v3.tailwindcss.com/docs/installation) for styling
-- [**Octokit**](https://github.com/octokit/rest.js/#readme) for pushing via a GitHub-compatible API (GitHub or Gitea)
+- [**Octokit**](https://github.com/octokit/rest.js/#readme) + provider adapters for GitHub and Gitea uploads
 - [**Nextcloud WebDAV**](https://docs.nextcloud.com/server/latest/developer_manual/client_apis/WebDAV/index.html) for Drive archiving with automatic versioning
 - [**Sharp**](https://sharp.pixelplumbing.com/install/) for server-side texture compression
 - [**npm lockfile + Coolify** (Docker)](https://coolify.io/docs/applications/build-packs/dockerfile) for hosting
@@ -206,7 +206,15 @@ lib/
 ├── diff-files.ts          # File diff classification (new/changed/unchanged/deleted)
 ├── sanitize.ts            # Filename sanitization
 ├── auth.ts                # Upload secret validation (timing-safe)
-├── github.ts              # Octokit helpers for GitHub-compatible remotes
+├── git/                   # Git provider layer selected by env
+│   ├── config.ts          # GIT_PROVIDER/GIT_REPO_URL/GIT_TOKEN parsing
+│   ├── content.ts         # Shared remote folder/file content helpers
+│   ├── http.ts            # Shared Git API request helpers
+│   ├── index.ts           # Public getRemoteFolder/pushAllToGit facade
+│   ├── lfs.ts             # Shared Git LFS upload helpers
+│   └── providers/
+│       ├── gitea.ts       # Gitea Contents API implementation
+│       └── github.ts      # GitHub Git Data API implementation
 ├── nextcloud.ts           # Nextcloud WebDAV client (native fetch, cached config)
 ├── upload-staging.ts      # Temporary server-side staging and prepared asset reuse
 ├── upload-lock.ts         # Lightweight in-memory per-folder upload lock
@@ -237,6 +245,7 @@ Copy `.env.example` to `.env.local` and fill in the values:
 
 ```env
 UPLOAD_SECRET_KEY=your-secret-key-here
+GIT_PROVIDER=gitea
 GIT_USERNAME=your-gitea-username
 GIT_TOKEN=your-git-provider-token
 GIT_BRANCH=main
@@ -251,6 +260,7 @@ NEXTCLOUD_BASE_PATH=Models
 | Variable | Description | Required |
 |----------|-------------|----------|
 | `UPLOAD_SECRET_KEY` | Secret key for upload authentication | Yes |
+| `GIT_PROVIDER` | Git provider adapter to use: `github` or `gitea`. If omitted, it is inferred from `GIT_REPO_URL` (`github.com` → GitHub, anything else → Gitea). | No |
 | `GIT_USERNAME` | Git username for Git LFS Basic auth on Gitea. Required for Gitea when LFS files are uploaded. | Gitea LFS |
 | `GIT_TOKEN` | Git provider token with repository read/write access. `GITHUB_TOKEN` is still accepted for backward compatibility. | Yes |
 | `GIT_BRANCH` | Target branch (default: main) | No |
@@ -262,6 +272,34 @@ NEXTCLOUD_BASE_PATH=Models
 
 > GitHub tokens need `Contents: Read and write`. Gitea tokens need repository read/write access.
 
+### Git provider selection
+
+The upload routes call a small provider layer in `lib/git/`:
+
+- `lib/git/config.ts` reads `GIT_PROVIDER`, `GIT_REPO_URL`, `GIT_TOKEN`, `GIT_USERNAME`, and `GIT_BRANCH`
+- `lib/git/providers/github.ts` handles GitHub commits with the Git Data API
+- `lib/git/providers/gitea.ts` handles Gitea commits with the Contents API
+- `lib/git/lfs.ts` handles Git LFS upload/auth for both providers
+
+For GitHub:
+
+```env
+GIT_PROVIDER=github
+GIT_TOKEN=ghp_xxx
+GIT_REPO_URL=https://github.com/org/repo.git
+GIT_BRANCH=main
+```
+
+For Gitea:
+
+```env
+GIT_PROVIDER=gitea
+GIT_USERNAME=your-gitea-username
+GIT_TOKEN=token_xxx
+GIT_REPO_URL=https://git.fabrik.mathieu-chavanel.fr/math-pixel/La-Fabrik
+GIT_BRANCH=main
+```
+
 > To create a Nextcloud public share token: Nextcloud > Files > select folder > Share > Create public share > set permissions (write access required) > copy the share link and extract the token
 
 ### Production (Coolify / Docker)
@@ -280,6 +318,7 @@ After a security patch:
 docker build -t upload-gltf .
 docker run -p 3000:3000 \
   -e UPLOAD_SECRET_KEY=your-key \
+  -e GIT_PROVIDER=gitea \
   -e GIT_USERNAME=your-gitea-username \
   -e GIT_TOKEN=token_xxx \
   -e GIT_REPO_URL=https://git.fabrik.mathieu-chavanel.fr/math-pixel/La-Fabrik \