Switch auth to plain-text password env var (remove bcrypt)

- Replace ADMIN_PASSWORD_HASH with ADMIN_PASSWORD in auth route and docker-compose
- Remove bcryptjs / @types/bcryptjs dependencies
- Delete scripts/hashPassword.ts (no longer needed)

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

.claude/settings.local.json

@@ -0,0 +1,14 @@
+{
+  "permissions": {
+    "allow": [
+      "Bash(npm install:*)",
+      "Bash(mkdir -p data)",
+      "Bash(DATABASE_URL=\"file:./data/rackmapper.db\" npx prisma migrate dev --name init)",
+      "Bash(npx prisma:*)",
+      "Bash(npx tsc:*)",
+      "Bash(git commit:*)",
+      "Bash(npm uninstall:*)",
+      "Bash(git add:*)"
+    ]
+  }
+}