Klarbild 1.0.0 — first public release

A self-hosted print studio: images at exact physical sizes, sheet layout with
crop marks, tiling, 1:1 PDF. Everything else — image generation, delivery,
share links, mail, Telegram — is an optional module that is off by default.

This is the neutral public twin of a private tool. Compared to that original:

- optional modules behind KLARBILD_MODULES; the default install is print-only
- English interface with German as a full second language (1,038 strings);
  the English sentence is the translation key
- no built-in accounts — first boot creates one admin from ADMIN_USERNAME /
  ADMIN_PASSWORD, or generates a password and logs it once
- delivery and backup targets are generic SFTP/FTPS endpoints, off by default
- English routes, English identifiers, English comments throughout
- two compose files: print-only by default, everything in the full one
- AGPL-3.0, CI (build, tests, type check, secret scan), CONTRIBUTING, SECURITY

124 tests green, type check clean, verified end to end against a live instance.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01Nh4A79bbqT9dcd2inzYUdg

CONTRIBUTING.md

@@ -0,0 +1,79 @@
+# Contributing
+
+Thanks for looking. Klarbild is a small project with one maintainer, so the most
+useful contributions are the ones that arrive ready to merge: a clear problem, a
+minimal change, and a test where a test is possible.
+
+## Getting it running
+
+```bash
+npm install
+cp .env.example .env     # DATABASE_URL, SESSION_SECRET, ENCRYPTION_KEY
+npm run dev
+```
+
+You need a PostgreSQL to point `DATABASE_URL` at; `docker compose up db` gives you
+one. Migrations run themselves on the first request.
+
+```bash
+npm test          # 124 tests, no database needed
+npx tsc --noEmit  # must be clean
+npm run build
+```
+
+Both `npm test` and `tsc` run in CI and both must be green.
+
+## How the code is laid out
+
+```
+src/lib/print*.ts     the print engine — pure arithmetic, heavily tested
+src/lib/paper.ts      86 image sizes, 19 paper formats, the size parser
+src/lib/modules.ts    which optional modules are switched on
+src/lib/i18n.ts       translation; the English sentence is the key
+src/components/       React islands, one per screen
+src/pages/            Astro pages and the API under src/pages/api/
+migrations/           numbered SQL, forward-only, idempotent, run on boot
+tests/                node:test, no framework
+```
+
+The rule that matters most: **the browser preview and the server-side PDF use the
+same layout code.** If you change how a sheet is laid out, change it in
+`src/lib/printlayout.ts` and both follow. Anything that recomputes geometry in a
+component is a bug waiting to happen.
+
+## House style
+
+- Comments explain **why**, and carry the number that justifies the decision.
+  "Measured: 440 MB of images peaked at 196 MB of memory" is worth more than
+  "stream the files". Please keep that habit; it is most of what makes this
+  codebase navigable.
+- No new dependency without a reason in the pull request. There are 20 runtime
+  dependencies and that is already plenty.
+- Two-space indent, no semicolon crusade, no reformatting of files you did not
+  otherwise touch.
+- Metric units. English decimal point in English strings.
+
+## Translation
+
+The English string in the source **is** the key. To add a language:
+
+1. Copy `src/locales/de.json` to `src/locales/<code>.json` and translate the values.
+2. Add the code to `LOCALES` and `LOCALE_NAMES` in `src/lib/i18n.ts`, and to
+   `DICTS` in `src/lib/i18n.server.ts`.
+
+A missing key falls back to English, so a partial translation is still useful. Never
+build a sentence by concatenation — use a named placeholder: `t('{done} of {total}
+done', { done, total })`.
+
+## Adding a module
+
+Optional features live behind `src/lib/modules.ts`. A new one needs: an entry in
+`MODULE_IDS` and `MODULE_INFO`, a `has('yours')` guard on its navigation entry and
+its settings card, and `if (!has('yours')) return moduleOff('yours')` at the top of
+every API route it owns. The test is simple — with the module off, the instance
+should not hint that the feature exists.
+
+## Pull requests
+
+One change per pull request. Say what breaks if it is wrong. If you found a bug you
+are not fixing, an issue with a reproduction is genuinely useful on its own.