chore: Halkyon Learn moves into apps/learn

Its server, client, app and curator, and the tools that write its
assets (maps, Anki fixtures, icons), as they are; paths are fixed in
the commits that follow.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Signed-off-by: Tizian 「ティツィアーン」 <raisondetredev@pm.me>

halkyon_learn_server/config/test.yaml

@@ -1,57 +0,0 @@
-# This is the configuration file for your test environment.
-# All ports are set to zero in this file which makes the server find the next available port.
-# This is needed to enable running tests concurrently. To set up your server, you will
-# need to add the name of the database you are connecting to and the user name.
-# The password for the database is stored in the config/passwords.yaml.
-#
-# When running your server locally, the server ports are the same as the public
-# facing ports.
-
-# Configuration for the main API test server.
-apiServer:
-  port: 0
-  publicHost: localhost
-  publicPort: 0
-  publicScheme: http
-
-# Configuration for the Insights test server.
-insightsServer:
-  port: 0
-  publicHost: localhost
-  publicPort: 0
-  publicScheme: http
-
-# Configuration for the web test server.
-webServer:
-  port: 0
-  publicHost: localhost
-  publicPort: 0
-  publicScheme: http
-
-# This is the database setup for your test server.
-database:
-  host: localhost
-  port: 9090
-  name: halkyon_learn_test
-  user: postgres
-  dataPath: .serverpod/test/pgdata
-  #maxConnectionCount: 10 # Defaults to 10, a negative or null value removes the limit
-
-# This is the setup for your Redis test instance.
-redis:
-  enabled: false
-  host: localhost
-  port: 9091
-  #user: # defaults to empty
-  #requireSsl: true # defaults to false
-
-sessionLogs:
-  persistentEnabled: false
-  consoleEnabled: true
-# consoleLogFormat: json # Defaults to "json", options are "text" or "json"
-
-# futureCallExecutionEnabled: true # Defaults to true
-
-#futureCall:
-#  concurrencyLimit: 1 # Defaults to 1, a negative or null value removes the limit
-#  scanInterval: 5000 # Unit in milliseconds, defaults to 5000