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>

apps/learn/halkyon_learn_server/migrations/20261013035552510-dictionary-keys/migration.json

@@ -0,0 +1,97 @@
+{
+  "__className__": "serverpod.DatabaseMigration",
+  "actions": [
+    {
+      "__className__": "serverpod.DatabaseMigrationAction",
+      "type": "createTable",
+      "createTable": {
+        "__className__": "serverpod.TableDefinition",
+        "name": "dictionary_key",
+        "dartName": "DictionaryKey",
+        "module": "halkyon_learn",
+        "schema": "public",
+        "columns": [
+          {
+            "__className__": "serverpod.ColumnDefinition",
+            "name": "id",
+            "fieldName": "id",
+            "columnType": 6,
+            "isNullable": false,
+            "columnDefault": "serial",
+            "dartType": "int?"
+          },
+          {
+            "__className__": "serverpod.ColumnDefinition",
+            "name": "source",
+            "fieldName": "source",
+            "columnType": 0,
+            "isNullable": false,
+            "dartType": "String"
+          },
+          {
+            "__className__": "serverpod.ColumnDefinition",
+            "name": "glossLanguage",
+            "fieldName": "glossLanguage",
+            "columnType": 0,
+            "isNullable": false,
+            "dartType": "String"
+          },
+          {
+            "__className__": "serverpod.ColumnDefinition",
+            "name": "key",
+            "fieldName": "key",
+            "columnType": 0,
+            "isNullable": false,
+            "dartType": "String"
+          },
+          {
+            "__className__": "serverpod.ColumnDefinition",
+            "name": "sourceId",
+            "fieldName": "sourceId",
+            "columnType": 0,
+            "isNullable": false,
+            "dartType": "String"
+          },
+          {
+            "__className__": "serverpod.ColumnDefinition",
+            "name": "rank",
+            "fieldName": "rank",
+            "columnType": 6,
+            "isNullable": false,
+            "dartType": "int"
+          }
+        ],
+        "foreignKeys": [],
+        "indexes": [
+          {
+            "__className__": "serverpod.IndexDefinition",
+            "indexName": "dictionary_key_idx",
+            "elements": [
+              {
+                "__className__": "serverpod.IndexElementDefinition",
+                "type": 0,
+                "definition": "source"
+              },
+              {
+                "__className__": "serverpod.IndexElementDefinition",
+                "type": 0,
+                "definition": "glossLanguage"
+              },
+              {
+                "__className__": "serverpod.IndexElementDefinition",
+                "type": 0,
+                "definition": "key"
+              }
+            ],
+            "type": "btree",
+            "isUnique": false,
+            "isPrimary": false
+          }
+        ],
+        "managed": true
+      }
+    }
+  ],
+  "warnings": [],
+  "migrationApiVersion": 1
+}

apps/learn/halkyon_learn_server/migrations/20261013035552510-dictionary-keys/migration.sql

@@ -0,0 +1,60 @@
+BEGIN;
+
+--
+-- ACTION CREATE TABLE
+--
+CREATE TABLE "dictionary_key" (
+    "id" bigserial PRIMARY KEY,
+    "source" text NOT NULL,
+    "glossLanguage" text NOT NULL,
+    "key" text NOT NULL,
+    "sourceId" text NOT NULL,
+    "rank" bigint NOT NULL
+);
+
+-- Indexes
+CREATE INDEX "dictionary_key_idx" ON "dictionary_key" USING btree ("source", "glossLanguage", "key");
+
+
+--
+-- MIGRATION VERSION FOR halkyon_learn
+--
+INSERT INTO "serverpod_migrations" ("module", "version", "timestamp")
+    VALUES ('halkyon_learn', '20261013035552510-dictionary-keys', now())
+    ON CONFLICT ("module")
+    DO UPDATE SET "version" = '20261013035552510-dictionary-keys', "timestamp" = now();
+
+--
+-- MIGRATION VERSION FOR serverpod
+--
+INSERT INTO "serverpod_migrations" ("module", "version", "timestamp")
+    VALUES ('serverpod', '20260824182259319', now())
+    ON CONFLICT ("module")
+    DO UPDATE SET "version" = '20260824182259319', "timestamp" = now();
+
+--
+-- MIGRATION VERSION FOR serverpod_auth_idp
+--
+INSERT INTO "serverpod_migrations" ("module", "version", "timestamp")
+    VALUES ('serverpod_auth_idp', '20260924105404509', now())
+    ON CONFLICT ("module")
+    DO UPDATE SET "version" = '20260924105404509', "timestamp" = now();
+
+--
+-- MIGRATION VERSION FOR serverpod_offline_sync
+--
+INSERT INTO "serverpod_migrations" ("module", "version", "timestamp")
+    VALUES ('serverpod_offline_sync', '20260914143806119', now())
+    ON CONFLICT ("module")
+    DO UPDATE SET "version" = '20260914143806119', "timestamp" = now();
+
+--
+-- MIGRATION VERSION FOR serverpod_auth_core
+--
+INSERT INTO "serverpod_migrations" ("module", "version", "timestamp")
+    VALUES ('serverpod_auth_core', '20260924105232991', now())
+    ON CONFLICT ("module")
+    DO UPDATE SET "version" = '20260924105232991', "timestamp" = now();
+
+
+COMMIT;