chore: add missing env vars to .env.example

Add 11 previously undocumented env vars: TEST_DB_HOST, TEST_DB_DSN, GO_TESTING, SQUARE_WEBHOOK_NOTIFICATION_URL, DAV_BASE_URL, DAV_ADMIN_PASSWORD, NO_COLOR, VITE_BACKEND_URL, RUSTFS_*

Ultraworked with [Sisyphus](https://github.com/code-yeongyu/oh-my-openagent)

Co-authored-by: Sisyphus <clio-agent@sisyphuslabs.ai>

.env.example

@@ -36,3 +36,32 @@ SQUARE_ACCESS_TOKEN=
 SQUARE_LOCATION_ID=
 SQUARE_ENVIRONMENT=mock
 SQUARE_WEBHOOK_SIGNATURE_KEY=
+SQUARE_WEBHOOK_NOTIFICATION_URL=
+
+# Test Database (separate from main DB)
+# Used by testutils/testdb for running tests without corrupting dev data
+TEST_DB_HOST=localhost
+TEST_DB_DSN=
+
+# Dev/CI mode — set to "true" to enable mock services
+# Disables zxcvbn password checks, skips artificial Square mock delays,
+# skips DAV sync, and relaxes production guardrails
+GO_TESTING=
+
+# CardDAV (SabreDAV) — profile photo sync
+DAV_BASE_URL=http://localhost:8080
+DAV_ADMIN_PASSWORD=admin
+
+# Logging
+# Set to "true" to disable ANSI color escape sequences in log output
+NO_COLOR=
+
+# Frontend
+VITE_BACKEND_URL=http://localhost:8080
+
+# Local S3 (Rustfs) — requires GO_TESTING=1 or dev build tag
+# These are dev-only overrides used by the dev S3 implementation
+RUSTFS_ENDPOINT=http://rustfs:9000
+RUSTFS_ACCESS_KEY=rustfsadmin
+RUSTFS_SECRET_KEY=rustfsadmin
+RUSTFS_BUCKET=crussell