docs(contributing): tell contributors to target dev (#412)

* fix(screenshots): sharp-Typen fuer 0.34 und 0.35 gleichzeitig (#410)

sharp 0.35 ist von `export =` auf ESM umgestellt: der Modul-Namespace
ist nicht mehr aufrufbar, die Factory sitzt unter .default. Der
Type-Check brach damit in scripts/screenshots.ts weg, sobald der
Next-Bump (#402) sharp von 0.34.5 auf 0.35.3 mitzieht -- sharp ist hier
keine deklarierte Dependency, sondern kommt ueber Next mit.

Die Form wird jetzt aus dem installierten Paket abgeleitet statt
festgeschrieben, zur Laufzeit wie im Typ. Geprueft mit beiden
Versionen: tsc laeuft mit 0.34.5 und mit 0.35.3 fehlerfrei durch.

Co-authored-by: ralksta <ralksta@users.noreply.github.com>
Co-authored-by: Claude Opus 5 (1M context) <noreply@anthropic.com>

* chore(deps): bump the nextjs group across 1 directory with 2 updates (#402)

Bumps the nextjs group with 2 updates in the / directory: [next](https://github.com/vercel/next.js) and [eslint-config-next](https://github.com/vercel/next.js/tree/HEAD/packages/eslint-config-next).


Updates `next` from 16.2.12 to 16.3.0
- [Release notes](https://github.com/vercel/next.js/releases)
- [Commits](https://github.com/vercel/next.js/compare/v16.2.12...v16.3.0)

Updates `eslint-config-next` from 16.2.12 to 16.3.0
- [Release notes](https://github.com/vercel/next.js/releases)
- [Commits](https://github.com/vercel/next.js/commits/v16.3.0/packages/eslint-config-next)

---
updated-dependencies:
- dependency-name: eslint-config-next
  dependency-version: 16.3.0
  dependency-type: direct:development
  update-type: version-update:semver-minor
  dependency-group: nextjs
- dependency-name: next
  dependency-version: 16.3.0
  dependency-type: direct:production
  update-type: version-update:semver-minor
  dependency-group: nextjs
...

Signed-off-by: dependabot[bot] <support@github.com>
Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>

* chore(deps-dev): bump prettier from 3.8.3 to 3.9.6 (#405)

Bumps [prettier](https://github.com/prettier/prettier) from 3.8.3 to 3.9.6.
- [Release notes](https://github.com/prettier/prettier/releases)
- [Changelog](https://github.com/prettier/prettier/blob/main/CHANGELOG.md)
- [Commits](https://github.com/prettier/prettier/compare/3.8.3...3.9.6)

---
updated-dependencies:
- dependency-name: prettier
  dependency-version: 3.9.6
  dependency-type: direct:development
  update-type: version-update:semver-minor
...

Signed-off-by: dependabot[bot] <support@github.com>
Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>

* docs(contributing): PRs gehen gegen dev

Nirgends stand, welcher Branch das Ziel ist -- die offene PR #398 zeigt
folgerichtig auf main. main bewegt sich aber nur ueber Releases: es wird
von dev fast-forwarded, getaggt, und der Tag stoesst den Image-Publish
an. Eine PR dagegen legt unveroeffentlichten Code in genau den Branch,
der dem publizierten Image entsprechen soll.

Steht jetzt als eigener Abschnitt in CONTRIBUTING.md, im Setup-Snippet
und in beiden Checklisten. Mit Hinweis, dass ein falsches Ziel ueber
"Edit" an der PR umgestellt werden kann, statt die Arbeit neu zu machen.

Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>

---------

Signed-off-by: dependabot[bot] <support@github.com>
Co-authored-by: ralksta <ralksta@users.noreply.github.com>
Co-authored-by: Claude Opus 5 (1M context) <noreply@anthropic.com>
Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>

CONTRIBUTING.md

@@ -9,12 +9,29 @@ Thanks for your interest in contributing! 🎉
 - **Pull requests** — see below
 - **Discussions** — [Ask questions or share ideas](https://github.com/ralksta/immich-folio/discussions)
 
+## Branches
+
+**Open pull requests against `dev`, not `main`.**
+
+`dev` is where everything is integrated. `main` only ever moves through a
+release: it is fast-forwarded from `dev`, tagged, and the tag triggers the
+Docker image publish. A PR against `main` would put unreleased code into the
+branch that is supposed to match the published image — so please branch off
+`dev` and target it.
+
+CI runs on pull requests to either branch, so a PR against `dev` is checked
+exactly the same way.
+
+If you opened a PR against `main` by accident, no need to redo the work — you
+can change the target branch on the PR page under **Edit** next to the title.
+
 ## Development setup
 
 ```bash
-# 1. Clone
+# 1. Clone and switch to the integration branch
 git clone https://github.com/ralksta/immich-folio.git
 cd immich-folio
+git checkout dev
 
 # 2. Install
 npm install
@@ -58,6 +75,7 @@ chore: bump next to 15.x
 
 ## Pull Request checklist
 
+- [ ] Targets `dev`
 - [ ] `npx tsc --noEmit` passes
 - [ ] `npx vitest run` passes
 - [ ] `npm run build` passes