fix: resolve 4 tag-blocking issues for v0.1.0

- README/CONTRIBUTING quick start: add UPTOP_ADMIN_KEY so SSH works on
  fresh DB, fix single-file go run path that doesn't compile
- apply --dry-run: assign placeholder IDs for new alerts and groups so
  resolveAlertID succeeds when monitors reference not-yet-created alerts
- deploy/*.yml: switch user-facing compose files from broken build
  context to image: lerkolabs/uptop:latest, fix dev context to ..

deploy/docker-compose.dev.yml

@@ -1,8 +1,8 @@
 services:
   # The Application
   app:
-    build: 
-      context: .
+    build:
+      context: ..
       dockerfile: Dockerfile
     container_name: uptop-dev
     ports: