chore: establish iteration 1 development baseline

README.md

@@ -1,2 +1,24 @@
-# labtimesheet
+# Lab Timesheet
 
+## Local development
+
+The application targets Java 25 and expects PostgreSQL on
+`localhost:55432` when the default `dev` profile is active. Override any local
+value with `LAB_DB_URL`, `LAB_DB_USERNAME`, `LAB_DB_PASSWORD`,
+`LAB_SMTP_HOST`, or `LAB_SMTP_PORT`.
+
+```bash
+export JAVA_HOME=/opt/homebrew/opt/openjdk@25
+export PATH="$JAVA_HOME/bin:$PATH"
+./mvnw spring-boot:run
+```
+
+Tests use PostgreSQL 18.4 through Testcontainers and do not use the developer
+database:
+
+```bash
+./mvnw test
+```
+
+Every feature test must have a companion Markdown evidence record under
+[`docs/tests`](docs/tests/README.md).