fix: correct malformed @Value annotations in DataInitializer

Missing closing braces caused Spring to inject the literal placeholder
string instead of resolving the property, silently ignoring any
app.admin.username / app.admin.password env-var overrides.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

CLAUDE.md

@@ -6,6 +6,22 @@ This file provides guidance to Claude Code (claude.ai/code) when working with co
 
 **Familienarchiv** is a family document archival system — a full-stack web app for digitizing, organizing, and searching family documents. Key features: file uploads (stored in MinIO/S3), metadata management, Excel batch import, full-text search, conversation threads between family members, and role-based access control.
 
+## Collaboration Principles
+
+**Be honest and objective**: Evaluate all suggestions, ideas, and feedback on their technical merits. Don't be overly complimentary or sycophantic. If something doesn't make sense, doesn't align with best practices, or could be improved, say so directly and constructively. Technical accuracy and project quality take precedence over being agreeable.
+
+## Core Workflow: Research → Plan → Implement → Validate
+
+**Start every feature with:** "Let me research the codebase and create a plan before implementing."
+
+1. **Research** - Understand existing patterns and architecture
+2. **Plan** - Propose approach and verify with you
+3. **Implement** - Build with tests and error handling
+4. **Validate** - ALWAYS run formatters, linters, and tests after implementation
+
+- Whenever working on a feature or issue, let's always come up with a plan first, then save it to a file called `/.agent/current-plan.md`, before getting started with code changes. Update this file as the work progresses.
+- Let's use pure functions where possible to improve readability and testing.
+
 ## Stack
 
 - **Backend**: Spring Boot 4.0 (Java 21, Maven, Jetty, JPA/Hibernate, Flyway, Spring Security, Spring Session JDBC)