feat(ntfy): add Ntfy::Publisher service with HTTP POST + auth

Gemfile.lock

@@ -98,6 +98,9 @@ GEM
     chunky_png (1.4.0)
     concurrent-ruby (1.3.5)
     connection_pool (2.5.4)
+    crack (1.0.1)
+      bigdecimal
+      rexml
     crass (1.0.6)
     csv (3.3.5)
     date (3.4.1)
@@ -116,6 +119,7 @@ GEM
       raabro (~> 1.4)
     globalid (1.3.0)
       activesupport (>= 6.1)
+    hashdiff (1.2.1)
     httparty (0.23.2)
       csv
       mini_mime (>= 1.0.0)
@@ -388,6 +392,10 @@ GEM
       activemodel (>= 6.0.0)
       bindex (>= 0.4.0)
       railties (>= 6.0.0)
+    webmock (3.26.2)
+      addressable (>= 2.8.0)
+      crack (>= 0.3.2)
+      hashdiff (>= 0.4.0, < 2.0.0)
     websocket (1.2.11)
     websocket-driver (0.8.0)
       base64
@@ -442,6 +450,7 @@ DEPENDENCIES
   turbo-rails
   tzinfo-data
   web-console
+  webmock
 
 BUNDLED WITH
    2.6.9