Add deterministic API key for uptime monitoring (#834)

* Preserve existing demo data by default

Add SKIP_CLEAR environment variable to demo_data rake tasks.
Defaults to true (preserving existing data). Set SKIP_CLEAR=0
to wipe data before generating new demo data.

https://claude.ai/code/session_01GcoMc2SH3czPrbeGkHbmpE

* Add deterministic instatus.com API key for demo data

Create a read-only API key named "instatus.com" with a fixed value
when generating demo data. This allows uptime monitoring tools to
use a hardcoded API key that doesn't change between demo data runs.

The key is idempotent - if it already exists, it will be reused.

https://claude.ai/code/session_01GcoMc2SH3czPrbeGkHbmpE

* OK to name instatus to a point

* Remove all Instatus references

* Rename to create_monitoring_api_key! and scope lookup to admin_user

- Rename create_instatus_api_key! to create_monitoring_api_key! (snake_case)
- Scope API key lookup to admin_user instead of global ApiKey lookup
- Each family's admin now has their own monitoring API key

https://claude.ai/code/session_01GcoMc2SH3czPrbeGkHbmpE

---------

Co-authored-by: Claude <noreply@anthropic.com>

lib/tasks/demo_data.rake

@@ -2,9 +2,10 @@ namespace :demo_data do
   desc "Load empty demo dataset (no financial data)"
   task empty: :environment do
     start = Time.now
-    puts "🚀 Loading EMPTY demo data…"
+    skip_clear = ENV.fetch("SKIP_CLEAR", "1") == "1"
+    puts "🚀 Loading EMPTY demo data#{skip_clear ? ' (preserving existing data)' : ' (clearing existing data)'}…"
 
-    Demo::Generator.new.generate_empty_data!
+    Demo::Generator.new.generate_empty_data!(skip_clear: skip_clear)
 
     puts "✅ Done in #{(Time.now - start).round(2)}s"
   end
@@ -12,9 +13,10 @@ namespace :demo_data do
   desc "Load new-user demo dataset (family created but not onboarded)"
   task new_user: :environment do
     start = Time.now
-    puts "🚀 Loading NEW-USER demo data…"
+    skip_clear = ENV.fetch("SKIP_CLEAR", "1") == "1"
+    puts "🚀 Loading NEW-USER demo data#{skip_clear ? ' (preserving existing data)' : ' (clearing existing data)'}…"
 
-    Demo::Generator.new.generate_new_user_data!
+    Demo::Generator.new.generate_new_user_data!(skip_clear: skip_clear)
 
     puts "✅ Done in #{(Time.now - start).round(2)}s"
   end
@@ -23,10 +25,11 @@ namespace :demo_data do
   task default: :environment do
     start    = Time.now
     seed     = ENV.fetch("SEED", Random.new_seed)
-    puts "🚀 Loading FULL demo data (seed=#{seed})…"
+    skip_clear = ENV.fetch("SKIP_CLEAR", "1") == "1"
+    puts "🚀 Loading FULL demo data (seed=#{seed})#{skip_clear ? ' (preserving existing data)' : ' (clearing existing data)'}…"
 
     generator = Demo::Generator.new(seed: seed)
-    generator.generate_default_data!
+    generator.generate_default_data!(skip_clear: skip_clear)
 
     validate_demo_data