fix(audit): address security audit findings

- Translate German error/warn messages in auth.js to English
- Add CODE_OF_CONDUCT.md (Contributor Covenant v2.1)
- Remove docs/claude-md-migration.md (internal migration artifact)
- Clarify README first-login instruction with credential hint

CODE_OF_CONDUCT.md

@@ -0,0 +1,54 @@
+# Contributor Covenant Code of Conduct
+
+## Our Pledge
+
+We as members, contributors, and leaders pledge to make participation in our
+community a harassment-free experience for everyone, regardless of age, body
+size, visible or invisible disability, ethnicity, sex characteristics, gender
+identity and expression, level of experience, education, socio-economic status,
+nationality, personal appearance, race, caste, color, religion, or sexual
+identity and orientation.
+
+We pledge to act and interact in ways that contribute to an open, welcoming,
+diverse, inclusive, and healthy community.
+
+## Our Standards
+
+Examples of behavior that contributes to a positive environment:
+
+* Demonstrating empathy and kindness toward other people
+* Being respectful of differing opinions, viewpoints, and experiences
+* Giving and gracefully accepting constructive feedback
+* Accepting responsibility and apologizing to those affected by our mistakes
+* Focusing on what is best not just for us as individuals, but for the overall community
+
+Examples of unacceptable behavior:
+
+* The use of sexualized language or imagery, and sexual attention or advances of any kind
+* Trolling, insulting or derogatory comments, and personal or political attacks
+* Public or private harassment
+* Publishing others' private information without their explicit permission
+* Other conduct which could reasonably be considered inappropriate in a professional setting
+
+## Enforcement Responsibilities
+
+Community leaders are responsible for clarifying and enforcing our standards of
+acceptable behavior and will take appropriate and fair corrective action in
+response to any behavior that they deem inappropriate, threatening, offensive,
+or harmful.
+
+## Scope
+
+This Code of Conduct applies within all community spaces, and also applies when
+an individual is officially representing the community in public spaces.
+
+## Enforcement
+
+Instances of abusive, harassing, or otherwise unacceptable behavior may be
+reported to the community leaders responsible for enforcement. All complaints
+will be reviewed and investigated promptly and fairly.
+
+## Attribution
+
+This Code of Conduct is adapted from the [Contributor Covenant](https://www.contributor-covenant.org),
+version 2.1, available at https://www.contributor-covenant.org/version/2/1/code_of_conduct.html.

README.md

@@ -72,7 +72,7 @@ docker compose up -d --build
 docker compose exec oikos node setup.js
 ```
 
-Then open `http://localhost:3000` and log in. Add family members from Settings.
+Then open `http://localhost:3000` and log in with the admin credentials you set in the previous step. Add family members from Settings.
 
 > **New to Docker?** The **[Installation Guide](docs/installation.md)** walks you through every step: From installing Docker to HTTPS setup, backups, and troubleshooting.
 

docs/claude-md-migration.md

@@ -1,48 +0,0 @@
-# CLAUDE.md Migration Summary
-
-## Result
-
-| | Lines |
-|---|---|
-| Before | 82 |
-| After | 50 |
-| Reduction | -39% (-32 lines) |
-
-## What was removed and why
-
-| Removed | Reason |
-|---|---|
-| `## Quick Reference` commands block (6 lines) | `npm start`, `npm run dev`, `npm test` are all in `package.json scripts`. Claude reads `package.json` on demand. `docker compose up -d` is a deployment detail, not a development constraint. |
-| "These are non-negotiable. Every violation is a bug." intro | Moved to tighter one-liner before the list. |
-| Full directory tree (21 lines) | Claude navigates the filesystem directly. Listing every file adds no behavioral value. Only non-obvious locations were kept. |
-| "Pages are ES modules" standalone paragraph | Merged into Conventions. |
-| Semicolons | Inferrable from reading any source file. |
-| Header comment convention | Already documented in `CONTRIBUTING.md`. |
-| DB table column pattern (`id`, `created_at`, `updated_at`) | Already in `CONTRIBUTING.md`. |
-| Commit format and Changelog instructions (2 lines) | Already in `CONTRIBUTING.md`. Claude can read it when committing. |
-| `## Current State` paragraph | Describes finished features - zero behavioral value. Becomes stale immediately. |
-| "When to consult" column from Reference table | Padding. Claude decides when to read reference docs based on task context. |
-
-## What moved to rules files
-
-None. The remaining content is either universal (applies to every file) or a short pointer. No subsystem-specific rules justify a separate file at this project size.
-
-## What was kept and why
-
-| Kept | Why |
-|---|---|
-| All 8 Hard Constraints | Each prevents a class of wrong code that Claude would otherwise produce. The no-frameworks rule in particular would be violated without an explicit reminder. |
-| API response shape `{data}` / `{error, code}` | Not inferrable without reading multiple route files. Applies to every new route. |
-| `formatDate()`/`formatTime()` | Without this, Claude formats dates manually (e.g. `new Date().toLocaleDateString()`), producing inconsistent output. |
-| `pages/*.js` → `render()`, no side effects | Structural contract not obvious from reading one page file. |
-| `oikos-` prefix | Web Component naming convention. |
-| Non-obvious file locations (`i18n.js`, `api.js`, `router.js`) | These live at `public/` root, not in a subdirectory. Easy to miss when navigating. |
-| Request flow one-liner | Architectural orientation for new tasks. |
-| Reference table (trimmed) | On-demand pointers replace inline content for spec details. |
-
-## Token delta estimate
-
-At ~4 chars/token average for this content:
-- Before: ~1,800 tokens loaded every session
-- After: ~1,100 tokens loaded every session
-- Savings: ~700 tokens per session

server/auth.js

@@ -93,10 +93,10 @@ const sessionStore = new BetterSQLiteStore();
  */
 if (!process.env.SESSION_SECRET) {
   if (process.env.NODE_ENV === 'production') {
-    throw new Error('[Auth] SESSION_SECRET muss in der .env gesetzt sein (Produktion).');
+    throw new Error('[Auth] SESSION_SECRET must be set in .env (production).');
   }
   process.env.SESSION_SECRET = randomBytes(32).toString('hex');
-  log.warn('SESSION_SECRET nicht gesetzt - zufaelliges Einmal-Secret generiert (Sessions ueberleben keinen Neustart).');
+  log.warn('SESSION_SECRET not set - generated ephemeral random secret (sessions will not survive restarts).');
 }
 
 const sessionMiddleware = session({