feat(todo,app): files attached to tasks and comments

Halkyon's ADR 0043, D1, D3, D5 and D8: any file up to 100 MB, attached to
a task's description or to a comment, sealed as everything of Todo's.

Server: the attachment table, synced and sealed as the others, with the
sealed file's hash readable for the store; todoFiles hands halkyon_base
its rows, readable by their space's members, and takes sealed files
alone; the files no attachment names go daily. Its tests hold downloads
to the row's space, refuse a readable file and prune what no live row
names. Migration attachments: CREATE TABLE "attachment" with its indexes
and the foreign key to its space, cascading as every synced table's.

App: AttachmentRepository seals each file for its row, keeps it sealed
and opened in the person's folder, uploads it after each sync and fetches
it as it shows, both held back by Without files on mobile data but for a
file tapped. Under the description and a comment's text, a row of them:
pictures as thumbnails opening full-size, other files as chips opening in
the system's app, else saved; the paperclip beside the description and in the comment's
composer adds them, the composer holding them until it is sent. A task deleted takes its files
and its comments' along, a comment its own.

halkyon_app opens a file in the system's app (FileOpener): on Android
through its plugin and a FileProvider of its own class, sharing the
cache's halkyon_opened/ folder alone; on the desktop as a file: URI.

Whats-New: Attach files to a task's description or a comment with the paperclip: pictures show as thumbnails, other files open in their app.
Whats-New-De: Hänge mit der Büroklammer Dateien an die Beschreibung einer Aufgabe oder an einen Kommentar: Bilder erscheinen als Vorschau, andere Dateien öffnen sich in ihrer App.
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/todo/halkyon_todo_server/migrations/20261110231607673-attachments/definition_project.json

@@ -0,0 +1,806 @@
+{
+  "__className__": "serverpod.DatabaseDefinition",
+  "schemaVersion": 2,
+  "moduleName": "halkyon_todo",
+  "tables": [
+    {
+      "__className__": "serverpod.TableDefinition",
+      "name": "attachment",
+      "dartName": "Attachment",
+      "module": "halkyon_todo",
+      "schema": "public",
+      "columns": [
+        {
+          "__className__": "serverpod.ColumnDefinition",
+          "name": "id",
+          "fieldName": "id",
+          "columnType": 7,
+          "isNullable": false,
+          "columnDefault": "random_v7",
+          "dartType": "UuidValue?"
+        },
+        {
+          "__className__": "serverpod.ColumnDefinition",
+          "name": "spaceId",
+          "fieldName": "spaceId",
+          "columnType": 6,
+          "isNullable": true,
+          "dartType": "int?"
+        },
+        {
+          "__className__": "serverpod.ColumnDefinition",
+          "name": "sha256",
+          "fieldName": "sha256",
+          "columnType": 0,
+          "isNullable": false,
+          "dartType": "String"
+        },
+        {
+          "__className__": "serverpod.ColumnDefinition",
+          "name": "keyId",
+          "fieldName": "keyId",
+          "columnType": 0,
+          "isNullable": true,
+          "dartType": "String?"
+        },
+        {
+          "__className__": "serverpod.ColumnDefinition",
+          "name": "payload",
+          "fieldName": "payload",
+          "columnType": 5,
+          "isNullable": false,
+          "dartType": "dart:typed_data:ByteData"
+        },
+        {
+          "__className__": "serverpod.ColumnDefinition",
+          "name": "nonce",
+          "fieldName": "nonce",
+          "columnType": 5,
+          "isNullable": true,
+          "dartType": "dart:typed_data:ByteData?"
+        }
+      ],
+      "foreignKeys": [
+        {
+          "__className__": "serverpod.ForeignKeyDefinition",
+          "constraintName": "attachment_fk_0",
+          "columns": [
+            "spaceId"
+          ],
+          "referenceTable": "offline_sync_spaces",
+          "referenceTableSchema": "public",
+          "referenceColumns": [
+            "id"
+          ],
+          "onUpdate": 3,
+          "onDelete": 4
+        }
+      ],
+      "indexes": [
+        {
+          "__className__": "serverpod.IndexDefinition",
+          "indexName": "attachment_space_idx",
+          "elements": [
+            {
+              "__className__": "serverpod.IndexElementDefinition",
+              "type": 0,
+              "definition": "spaceId"
+            }
+          ],
+          "type": "btree",
+          "isUnique": false,
+          "isPrimary": false
+        },
+        {
+          "__className__": "serverpod.IndexDefinition",
+          "indexName": "attachment_hash_idx",
+          "elements": [
+            {
+              "__className__": "serverpod.IndexElementDefinition",
+              "type": 0,
+              "definition": "spaceId"
+            },
+            {
+              "__className__": "serverpod.IndexElementDefinition",
+              "type": 0,
+              "definition": "sha256"
+            }
+          ],
+          "type": "btree",
+          "isUnique": false,
+          "isPrimary": false
+        }
+      ],
+      "managed": true
+    },
+    {
+      "__className__": "serverpod.TableDefinition",
+      "name": "content_key",
+      "dartName": "ContentKey",
+      "module": "halkyon_todo",
+      "schema": "public",
+      "columns": [
+        {
+          "__className__": "serverpod.ColumnDefinition",
+          "name": "id",
+          "fieldName": "id",
+          "columnType": 7,
+          "isNullable": false,
+          "columnDefault": "random_v7",
+          "dartType": "UuidValue?"
+        },
+        {
+          "__className__": "serverpod.ColumnDefinition",
+          "name": "spaceId",
+          "fieldName": "spaceId",
+          "columnType": 6,
+          "isNullable": true,
+          "dartType": "int?"
+        },
+        {
+          "__className__": "serverpod.ColumnDefinition",
+          "name": "dataKeyId",
+          "fieldName": "dataKeyId",
+          "columnType": 0,
+          "isNullable": false,
+          "dartType": "String"
+        },
+        {
+          "__className__": "serverpod.ColumnDefinition",
+          "name": "sealedKey",
+          "fieldName": "sealedKey",
+          "columnType": 5,
+          "isNullable": false,
+          "dartType": "dart:typed_data:ByteData"
+        }
+      ],
+      "foreignKeys": [
+        {
+          "__className__": "serverpod.ForeignKeyDefinition",
+          "constraintName": "content_key_fk_0",
+          "columns": [
+            "spaceId"
+          ],
+          "referenceTable": "offline_sync_spaces",
+          "referenceTableSchema": "public",
+          "referenceColumns": [
+            "id"
+          ],
+          "onUpdate": 3,
+          "onDelete": 4
+        }
+      ],
+      "indexes": [
+        {
+          "__className__": "serverpod.IndexDefinition",
+          "indexName": "content_key_space_idx",
+          "elements": [
+            {
+              "__className__": "serverpod.IndexElementDefinition",
+              "type": 0,
+              "definition": "spaceId"
+            }
+          ],
+          "type": "btree",
+          "isUnique": false,
+          "isPrimary": false
+        }
+      ],
+      "managed": true
+    },
+    {
+      "__className__": "serverpod.TableDefinition",
+      "name": "label",
+      "dartName": "Label",
+      "module": "halkyon_todo",
+      "schema": "public",
+      "columns": [
+        {
+          "__className__": "serverpod.ColumnDefinition",
+          "name": "id",
+          "fieldName": "id",
+          "columnType": 7,
+          "isNullable": false,
+          "columnDefault": "random_v7",
+          "dartType": "UuidValue?"
+        },
+        {
+          "__className__": "serverpod.ColumnDefinition",
+          "name": "spaceId",
+          "fieldName": "spaceId",
+          "columnType": 6,
+          "isNullable": true,
+          "dartType": "int?"
+        },
+        {
+          "__className__": "serverpod.ColumnDefinition",
+          "name": "keyId",
+          "fieldName": "keyId",
+          "columnType": 0,
+          "isNullable": true,
+          "dartType": "String?"
+        },
+        {
+          "__className__": "serverpod.ColumnDefinition",
+          "name": "payload",
+          "fieldName": "payload",
+          "columnType": 5,
+          "isNullable": false,
+          "dartType": "dart:typed_data:ByteData"
+        },
+        {
+          "__className__": "serverpod.ColumnDefinition",
+          "name": "nonce",
+          "fieldName": "nonce",
+          "columnType": 5,
+          "isNullable": true,
+          "dartType": "dart:typed_data:ByteData?"
+        }
+      ],
+      "foreignKeys": [
+        {
+          "__className__": "serverpod.ForeignKeyDefinition",
+          "constraintName": "label_fk_0",
+          "columns": [
+            "spaceId"
+          ],
+          "referenceTable": "offline_sync_spaces",
+          "referenceTableSchema": "public",
+          "referenceColumns": [
+            "id"
+          ],
+          "onUpdate": 3,
+          "onDelete": 4
+        }
+      ],
+      "indexes": [
+        {
+          "__className__": "serverpod.IndexDefinition",
+          "indexName": "label_space_idx",
+          "elements": [
+            {
+              "__className__": "serverpod.IndexElementDefinition",
+              "type": 0,
+              "definition": "spaceId"
+            }
+          ],
+          "type": "btree",
+          "isUnique": false,
+          "isPrimary": false
+        }
+      ],
+      "managed": true
+    },
+    {
+      "__className__": "serverpod.TableDefinition",
+      "name": "project",
+      "dartName": "Project",
+      "module": "halkyon_todo",
+      "schema": "public",
+      "columns": [
+        {
+          "__className__": "serverpod.ColumnDefinition",
+          "name": "id",
+          "fieldName": "id",
+          "columnType": 7,
+          "isNullable": false,
+          "columnDefault": "random_v7",
+          "dartType": "UuidValue?"
+        },
+        {
+          "__className__": "serverpod.ColumnDefinition",
+          "name": "spaceId",
+          "fieldName": "spaceId",
+          "columnType": 6,
+          "isNullable": true,
+          "dartType": "int?"
+        },
+        {
+          "__className__": "serverpod.ColumnDefinition",
+          "name": "keyId",
+          "fieldName": "keyId",
+          "columnType": 0,
+          "isNullable": true,
+          "dartType": "String?"
+        },
+        {
+          "__className__": "serverpod.ColumnDefinition",
+          "name": "payload",
+          "fieldName": "payload",
+          "columnType": 5,
+          "isNullable": false,
+          "dartType": "dart:typed_data:ByteData"
+        },
+        {
+          "__className__": "serverpod.ColumnDefinition",
+          "name": "nonce",
+          "fieldName": "nonce",
+          "columnType": 5,
+          "isNullable": true,
+          "dartType": "dart:typed_data:ByteData?"
+        }
+      ],
+      "foreignKeys": [
+        {
+          "__className__": "serverpod.ForeignKeyDefinition",
+          "constraintName": "project_fk_0",
+          "columns": [
+            "spaceId"
+          ],
+          "referenceTable": "offline_sync_spaces",
+          "referenceTableSchema": "public",
+          "referenceColumns": [
+            "id"
+          ],
+          "onUpdate": 3,
+          "onDelete": 4
+        }
+      ],
+      "indexes": [
+        {
+          "__className__": "serverpod.IndexDefinition",
+          "indexName": "project_space_idx",
+          "elements": [
+            {
+              "__className__": "serverpod.IndexElementDefinition",
+              "type": 0,
+              "definition": "spaceId"
+            }
+          ],
+          "type": "btree",
+          "isUnique": false,
+          "isPrimary": false
+        }
+      ],
+      "managed": true
+    },
+    {
+      "__className__": "serverpod.TableDefinition",
+      "name": "saved_filter",
+      "dartName": "SavedFilter",
+      "module": "halkyon_todo",
+      "schema": "public",
+      "columns": [
+        {
+          "__className__": "serverpod.ColumnDefinition",
+          "name": "id",
+          "fieldName": "id",
+          "columnType": 7,
+          "isNullable": false,
+          "columnDefault": "random_v7",
+          "dartType": "UuidValue?"
+        },
+        {
+          "__className__": "serverpod.ColumnDefinition",
+          "name": "spaceId",
+          "fieldName": "spaceId",
+          "columnType": 6,
+          "isNullable": true,
+          "dartType": "int?"
+        },
+        {
+          "__className__": "serverpod.ColumnDefinition",
+          "name": "keyId",
+          "fieldName": "keyId",
+          "columnType": 0,
+          "isNullable": true,
+          "dartType": "String?"
+        },
+        {
+          "__className__": "serverpod.ColumnDefinition",
+          "name": "payload",
+          "fieldName": "payload",
+          "columnType": 5,
+          "isNullable": false,
+          "dartType": "dart:typed_data:ByteData"
+        },
+        {
+          "__className__": "serverpod.ColumnDefinition",
+          "name": "nonce",
+          "fieldName": "nonce",
+          "columnType": 5,
+          "isNullable": true,
+          "dartType": "dart:typed_data:ByteData?"
+        }
+      ],
+      "foreignKeys": [
+        {
+          "__className__": "serverpod.ForeignKeyDefinition",
+          "constraintName": "saved_filter_fk_0",
+          "columns": [
+            "spaceId"
+          ],
+          "referenceTable": "offline_sync_spaces",
+          "referenceTableSchema": "public",
+          "referenceColumns": [
+            "id"
+          ],
+          "onUpdate": 3,
+          "onDelete": 4
+        }
+      ],
+      "indexes": [
+        {
+          "__className__": "serverpod.IndexDefinition",
+          "indexName": "saved_filter_space_idx",
+          "elements": [
+            {
+              "__className__": "serverpod.IndexElementDefinition",
+              "type": 0,
+              "definition": "spaceId"
+            }
+          ],
+          "type": "btree",
+          "isUnique": false,
+          "isPrimary": false
+        }
+      ],
+      "managed": true
+    },
+    {
+      "__className__": "serverpod.TableDefinition",
+      "name": "section",
+      "dartName": "Section",
+      "module": "halkyon_todo",
+      "schema": "public",
+      "columns": [
+        {
+          "__className__": "serverpod.ColumnDefinition",
+          "name": "id",
+          "fieldName": "id",
+          "columnType": 7,
+          "isNullable": false,
+          "columnDefault": "random_v7",
+          "dartType": "UuidValue?"
+        },
+        {
+          "__className__": "serverpod.ColumnDefinition",
+          "name": "spaceId",
+          "fieldName": "spaceId",
+          "columnType": 6,
+          "isNullable": true,
+          "dartType": "int?"
+        },
+        {
+          "__className__": "serverpod.ColumnDefinition",
+          "name": "keyId",
+          "fieldName": "keyId",
+          "columnType": 0,
+          "isNullable": true,
+          "dartType": "String?"
+        },
+        {
+          "__className__": "serverpod.ColumnDefinition",
+          "name": "payload",
+          "fieldName": "payload",
+          "columnType": 5,
+          "isNullable": false,
+          "dartType": "dart:typed_data:ByteData"
+        },
+        {
+          "__className__": "serverpod.ColumnDefinition",
+          "name": "nonce",
+          "fieldName": "nonce",
+          "columnType": 5,
+          "isNullable": true,
+          "dartType": "dart:typed_data:ByteData?"
+        }
+      ],
+      "foreignKeys": [
+        {
+          "__className__": "serverpod.ForeignKeyDefinition",
+          "constraintName": "section_fk_0",
+          "columns": [
+            "spaceId"
+          ],
+          "referenceTable": "offline_sync_spaces",
+          "referenceTableSchema": "public",
+          "referenceColumns": [
+            "id"
+          ],
+          "onUpdate": 3,
+          "onDelete": 4
+        }
+      ],
+      "indexes": [
+        {
+          "__className__": "serverpod.IndexDefinition",
+          "indexName": "section_space_idx",
+          "elements": [
+            {
+              "__className__": "serverpod.IndexElementDefinition",
+              "type": 0,
+              "definition": "spaceId"
+            }
+          ],
+          "type": "btree",
+          "isUnique": false,
+          "isPrimary": false
+        }
+      ],
+      "managed": true
+    },
+    {
+      "__className__": "serverpod.TableDefinition",
+      "name": "task",
+      "dartName": "Task",
+      "module": "halkyon_todo",
+      "schema": "public",
+      "columns": [
+        {
+          "__className__": "serverpod.ColumnDefinition",
+          "name": "id",
+          "fieldName": "id",
+          "columnType": 7,
+          "isNullable": false,
+          "columnDefault": "random_v7",
+          "dartType": "UuidValue?"
+        },
+        {
+          "__className__": "serverpod.ColumnDefinition",
+          "name": "spaceId",
+          "fieldName": "spaceId",
+          "columnType": 6,
+          "isNullable": true,
+          "dartType": "int?"
+        },
+        {
+          "__className__": "serverpod.ColumnDefinition",
+          "name": "keyId",
+          "fieldName": "keyId",
+          "columnType": 0,
+          "isNullable": true,
+          "dartType": "String?"
+        },
+        {
+          "__className__": "serverpod.ColumnDefinition",
+          "name": "payload",
+          "fieldName": "payload",
+          "columnType": 5,
+          "isNullable": false,
+          "dartType": "dart:typed_data:ByteData"
+        },
+        {
+          "__className__": "serverpod.ColumnDefinition",
+          "name": "nonce",
+          "fieldName": "nonce",
+          "columnType": 5,
+          "isNullable": true,
+          "dartType": "dart:typed_data:ByteData?"
+        }
+      ],
+      "foreignKeys": [
+        {
+          "__className__": "serverpod.ForeignKeyDefinition",
+          "constraintName": "task_fk_0",
+          "columns": [
+            "spaceId"
+          ],
+          "referenceTable": "offline_sync_spaces",
+          "referenceTableSchema": "public",
+          "referenceColumns": [
+            "id"
+          ],
+          "onUpdate": 3,
+          "onDelete": 4
+        }
+      ],
+      "indexes": [
+        {
+          "__className__": "serverpod.IndexDefinition",
+          "indexName": "task_space_idx",
+          "elements": [
+            {
+              "__className__": "serverpod.IndexElementDefinition",
+              "type": 0,
+              "definition": "spaceId"
+            }
+          ],
+          "type": "btree",
+          "isUnique": false,
+          "isPrimary": false
+        }
+      ],
+      "managed": true
+    },
+    {
+      "__className__": "serverpod.TableDefinition",
+      "name": "task_comment",
+      "dartName": "TaskComment",
+      "module": "halkyon_todo",
+      "schema": "public",
+      "columns": [
+        {
+          "__className__": "serverpod.ColumnDefinition",
+          "name": "id",
+          "fieldName": "id",
+          "columnType": 7,
+          "isNullable": false,
+          "columnDefault": "random_v7",
+          "dartType": "UuidValue?"
+        },
+        {
+          "__className__": "serverpod.ColumnDefinition",
+          "name": "spaceId",
+          "fieldName": "spaceId",
+          "columnType": 6,
+          "isNullable": true,
+          "dartType": "int?"
+        },
+        {
+          "__className__": "serverpod.ColumnDefinition",
+          "name": "keyId",
+          "fieldName": "keyId",
+          "columnType": 0,
+          "isNullable": true,
+          "dartType": "String?"
+        },
+        {
+          "__className__": "serverpod.ColumnDefinition",
+          "name": "payload",
+          "fieldName": "payload",
+          "columnType": 5,
+          "isNullable": false,
+          "dartType": "dart:typed_data:ByteData"
+        },
+        {
+          "__className__": "serverpod.ColumnDefinition",
+          "name": "nonce",
+          "fieldName": "nonce",
+          "columnType": 5,
+          "isNullable": true,
+          "dartType": "dart:typed_data:ByteData?"
+        }
+      ],
+      "foreignKeys": [
+        {
+          "__className__": "serverpod.ForeignKeyDefinition",
+          "constraintName": "task_comment_fk_0",
+          "columns": [
+            "spaceId"
+          ],
+          "referenceTable": "offline_sync_spaces",
+          "referenceTableSchema": "public",
+          "referenceColumns": [
+            "id"
+          ],
+          "onUpdate": 3,
+          "onDelete": 4
+        }
+      ],
+      "indexes": [
+        {
+          "__className__": "serverpod.IndexDefinition",
+          "indexName": "task_comment_space_idx",
+          "elements": [
+            {
+              "__className__": "serverpod.IndexElementDefinition",
+              "type": 0,
+              "definition": "spaceId"
+            }
+          ],
+          "type": "btree",
+          "isUnique": false,
+          "isPrimary": false
+        }
+      ],
+      "managed": true
+    },
+    {
+      "__className__": "serverpod.TableDefinition",
+      "name": "todo_settings",
+      "dartName": "TodoSettings",
+      "module": "halkyon_todo",
+      "schema": "public",
+      "columns": [
+        {
+          "__className__": "serverpod.ColumnDefinition",
+          "name": "id",
+          "fieldName": "id",
+          "columnType": 7,
+          "isNullable": false,
+          "columnDefault": "random_v7",
+          "dartType": "UuidValue?"
+        },
+        {
+          "__className__": "serverpod.ColumnDefinition",
+          "name": "spaceId",
+          "fieldName": "spaceId",
+          "columnType": 6,
+          "isNullable": true,
+          "dartType": "int?"
+        },
+        {
+          "__className__": "serverpod.ColumnDefinition",
+          "name": "keyId",
+          "fieldName": "keyId",
+          "columnType": 0,
+          "isNullable": true,
+          "dartType": "String?"
+        },
+        {
+          "__className__": "serverpod.ColumnDefinition",
+          "name": "payload",
+          "fieldName": "payload",
+          "columnType": 5,
+          "isNullable": false,
+          "dartType": "dart:typed_data:ByteData"
+        },
+        {
+          "__className__": "serverpod.ColumnDefinition",
+          "name": "nonce",
+          "fieldName": "nonce",
+          "columnType": 5,
+          "isNullable": true,
+          "dartType": "dart:typed_data:ByteData?"
+        }
+      ],
+      "foreignKeys": [
+        {
+          "__className__": "serverpod.ForeignKeyDefinition",
+          "constraintName": "todo_settings_fk_0",
+          "columns": [
+            "spaceId"
+          ],
+          "referenceTable": "offline_sync_spaces",
+          "referenceTableSchema": "public",
+          "referenceColumns": [
+            "id"
+          ],
+          "onUpdate": 3,
+          "onDelete": 4
+        }
+      ],
+      "indexes": [
+        {
+          "__className__": "serverpod.IndexDefinition",
+          "indexName": "todo_settings_space_idx",
+          "elements": [
+            {
+              "__className__": "serverpod.IndexElementDefinition",
+              "type": 0,
+              "definition": "spaceId"
+            }
+          ],
+          "type": "btree",
+          "isUnique": false,
+          "isPrimary": false
+        }
+      ],
+      "managed": true
+    }
+  ],
+  "installedModules": [
+    {
+      "__className__": "serverpod.DatabaseMigrationVersion",
+      "module": "halkyon_base",
+      "version": "20261110225132890-file-store"
+    },
+    {
+      "__className__": "serverpod.DatabaseMigrationVersion",
+      "module": "serverpod",
+      "version": "20260824182259319"
+    },
+    {
+      "__className__": "serverpod.DatabaseMigrationVersion",
+      "module": "serverpod_auth_idp",
+      "version": "20260924105404509"
+    },
+    {
+      "__className__": "serverpod.DatabaseMigrationVersion",
+      "module": "serverpod_offline_sync",
+      "version": "20260914143806119"
+    },
+    {
+      "__className__": "serverpod.DatabaseMigrationVersion",
+      "module": "halkyon_oidc",
+      "version": "20261023180644988"
+    },
+    {
+      "__className__": "serverpod.DatabaseMigrationVersion",
+      "module": "serverpod_auth_core",
+      "version": "20260924105232991"
+    }
+  ],
+  "migrationApiVersion": 1
+}

apps/todo/halkyon_todo_server/migrations/20261110231607673-attachments/migration.json

@@ -0,0 +1,121 @@
+{
+  "__className__": "serverpod.DatabaseMigration",
+  "actions": [
+    {
+      "__className__": "serverpod.DatabaseMigrationAction",
+      "type": "createTable",
+      "createTable": {
+        "__className__": "serverpod.TableDefinition",
+        "name": "attachment",
+        "dartName": "Attachment",
+        "module": "halkyon_todo",
+        "schema": "public",
+        "columns": [
+          {
+            "__className__": "serverpod.ColumnDefinition",
+            "name": "id",
+            "fieldName": "id",
+            "columnType": 7,
+            "isNullable": false,
+            "columnDefault": "random_v7",
+            "dartType": "UuidValue?"
+          },
+          {
+            "__className__": "serverpod.ColumnDefinition",
+            "name": "spaceId",
+            "fieldName": "spaceId",
+            "columnType": 6,
+            "isNullable": true,
+            "dartType": "int?"
+          },
+          {
+            "__className__": "serverpod.ColumnDefinition",
+            "name": "sha256",
+            "fieldName": "sha256",
+            "columnType": 0,
+            "isNullable": false,
+            "dartType": "String"
+          },
+          {
+            "__className__": "serverpod.ColumnDefinition",
+            "name": "keyId",
+            "fieldName": "keyId",
+            "columnType": 0,
+            "isNullable": true,
+            "dartType": "String?"
+          },
+          {
+            "__className__": "serverpod.ColumnDefinition",
+            "name": "payload",
+            "fieldName": "payload",
+            "columnType": 5,
+            "isNullable": false,
+            "dartType": "dart:typed_data:ByteData"
+          },
+          {
+            "__className__": "serverpod.ColumnDefinition",
+            "name": "nonce",
+            "fieldName": "nonce",
+            "columnType": 5,
+            "isNullable": true,
+            "dartType": "dart:typed_data:ByteData?"
+          }
+        ],
+        "foreignKeys": [
+          {
+            "__className__": "serverpod.ForeignKeyDefinition",
+            "constraintName": "attachment_fk_0",
+            "columns": [
+              "spaceId"
+            ],
+            "referenceTable": "offline_sync_spaces",
+            "referenceTableSchema": "public",
+            "referenceColumns": [
+              "id"
+            ],
+            "onUpdate": 3,
+            "onDelete": 4
+          }
+        ],
+        "indexes": [
+          {
+            "__className__": "serverpod.IndexDefinition",
+            "indexName": "attachment_space_idx",
+            "elements": [
+              {
+                "__className__": "serverpod.IndexElementDefinition",
+                "type": 0,
+                "definition": "spaceId"
+              }
+            ],
+            "type": "btree",
+            "isUnique": false,
+            "isPrimary": false
+          },
+          {
+            "__className__": "serverpod.IndexDefinition",
+            "indexName": "attachment_hash_idx",
+            "elements": [
+              {
+                "__className__": "serverpod.IndexElementDefinition",
+                "type": 0,
+                "definition": "spaceId"
+              },
+              {
+                "__className__": "serverpod.IndexElementDefinition",
+                "type": 0,
+                "definition": "sha256"
+              }
+            ],
+            "type": "btree",
+            "isUnique": false,
+            "isPrimary": false
+          }
+        ],
+        "managed": true
+      }
+    }
+  ],
+  "warnings": [],
+  "migrationApiVersion": 1
+}

apps/todo/halkyon_todo_server/migrations/20261110231607673-attachments/migration.sql

@@ -0,0 +1,116 @@
+BEGIN;
+
+--
+-- Function: gen_random_uuid_v7()
+-- Source: https://gist.github.com/kjmph/5bd772b2c2df145aa645b837da7eca74
+-- License: MIT (copyright notice included on the generator source code).
+--
+create or replace function gen_random_uuid_v7()
+returns uuid
+as $$
+begin
+  -- use random v4 uuid as starting point (which has the same variant we need)
+  -- then overlay timestamp
+  -- then set version 7 by flipping the 2 and 1 bit in the version 4 string
+  return encode(
+    set_bit(
+      set_bit(
+        overlay(uuid_send(gen_random_uuid())
+                placing substring(int8send(floor(extract(epoch from clock_timestamp()) * 1000)::bigint) from 3)
+                from 1 for 6
+        ),
+        52, 1
+      ),
+      53, 1
+    ),
+    'hex')::uuid;
+end
+$$
+language plpgsql
+volatile;
+
+--
+-- ACTION CREATE TABLE
+--
+CREATE TABLE "attachment" (
+    "id" uuid PRIMARY KEY DEFAULT gen_random_uuid_v7(),
+    "spaceId" bigint,
+    "sha256" text NOT NULL,
+    "keyId" text,
+    "payload" bytea NOT NULL,
+    "nonce" bytea
+);
+
+-- Indexes
+CREATE INDEX "attachment_space_idx" ON "attachment" USING btree ("spaceId");
+CREATE INDEX "attachment_hash_idx" ON "attachment" USING btree ("spaceId", "sha256");
+
+--
+-- ACTION CREATE FOREIGN KEY
+--
+ALTER TABLE ONLY "attachment"
+    ADD CONSTRAINT "attachment_fk_0"
+    FOREIGN KEY("spaceId")
+    REFERENCES "offline_sync_spaces"("id")
+    ON DELETE CASCADE
+    ON UPDATE NO ACTION;
+
+
+--
+-- MIGRATION VERSION FOR halkyon_todo
+--
+INSERT INTO "serverpod_migrations" ("module", "version", "timestamp")
+    VALUES ('halkyon_todo', '20261110231607673-attachments', now())
+    ON CONFLICT ("module")
+    DO UPDATE SET "version" = '20261110231607673-attachments', "timestamp" = now();
+
+--
+-- MIGRATION VERSION FOR halkyon_base
+--
+INSERT INTO "serverpod_migrations" ("module", "version", "timestamp")
+    VALUES ('halkyon_base', '20261110225132890-file-store', now())
+    ON CONFLICT ("module")
+    DO UPDATE SET "version" = '20261110225132890-file-store', "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 halkyon_oidc
+--
+INSERT INTO "serverpod_migrations" ("module", "version", "timestamp")
+    VALUES ('halkyon_oidc', '20261023180644988', now())
+    ON CONFLICT ("module")
+    DO UPDATE SET "version" = '20261023180644988', "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;

apps/todo/halkyon_todo_server/migrations/migration_registry.txt

@@ -27,3 +27,4 @@
 20261106183802735-filters
 20261106184947570-comments
 20261110225635732-file-store
+20261110231607673-attachments