feat(drive): start implementation of drive

- add storage.drives
    - prepare migration phase
    - add created_by and updated_by on storage.folders

src/application/dtos/drive_dto.rs

@@ -0,0 +1,70 @@
+//! DTOs for the `/api/drives` endpoint surface.
+//!
+//! D0 surfaces only the read-only list. Mutating endpoints
+//! (`POST /api/drives` for shared-drive creation, `PATCH` for rename /
+//! policy edits, membership APIs) land in D2/D3.
+
+use serde::{Deserialize, Serialize};
+use utoipa::ToSchema;
+use uuid::Uuid;
+
+use crate::domain::entities::drive::{Drive, DriveKind};
+
+#[derive(Debug, Clone, Copy, Serialize, Deserialize, ToSchema, PartialEq, Eq)]
+#[serde(rename_all = "lowercase")]
+pub enum DriveKindDto {
+    Personal,
+    Shared,
+}
+
+impl From<DriveKind> for DriveKindDto {
+    fn from(k: DriveKind) -> Self {
+        match k {
+            DriveKind::Personal => DriveKindDto::Personal,
+            DriveKind::Shared => DriveKindDto::Shared,
+        }
+    }
+}
+
+/// One row in `GET /api/drives` — a drive the caller can read.
+///
+/// `default_for_user` is `Some(<caller_id>)` for the caller's default
+/// Personal drive and `None` otherwise. The picker UI uses this to put
+/// the default at the top of the list and mark it as "your home".
+#[derive(Debug, Clone, Serialize, ToSchema)]
+pub struct DriveDto {
+    pub id: Uuid,
+    pub name: String,
+    pub kind: DriveKindDto,
+    #[serde(skip_serializing_if = "Option::is_none")]
+    pub default_for_user: Option<Uuid>,
+    /// Storage cap in bytes. `None` means "no quota" (admin override /
+    /// future system drives).
+    #[serde(skip_serializing_if = "Option::is_none")]
+    pub quota_bytes: Option<i64>,
+    /// Running total of bytes consumed. Maintained incrementally in D4;
+    /// on D0 this reflects the backfilled baseline.
+    pub used_bytes: i64,
+    /// Capability-flag bag — clients render UI affordances based on
+    /// known keys (`forbid_public_links`, `include_in_photo_index`,
+    /// `forbid_music_index`, …). Unknown keys preserved verbatim.
+    pub policies: serde_json::Value,
+    pub created_at: chrono::DateTime<chrono::Utc>,
+    pub updated_at: chrono::DateTime<chrono::Utc>,
+}
+
+impl From<Drive> for DriveDto {
+    fn from(d: Drive) -> Self {
+        Self {
+            id: d.id,
+            name: d.name,
+            kind: d.kind.into(),
+            default_for_user: d.default_for_user,
+            quota_bytes: d.quota_bytes,
+            used_bytes: d.used_bytes,
+            policies: d.policies,
+            created_at: d.created_at,
+            updated_at: d.updated_at,
+        }
+    }
+}

src/application/dtos/grant_dto.rs

@@ -58,6 +58,7 @@ impl From<Subject> for SubjectDto {
 pub enum ResourceTypeDto {
     Folder,
     File,
+    Drive,
 }
 
 #[derive(Debug, Clone, Serialize, Deserialize, ToSchema)]
@@ -72,6 +73,7 @@ impl From<ResourceDto> for Resource {
         match dto.kind {
             ResourceTypeDto::Folder => Resource::Folder(dto.id),
             ResourceTypeDto::File => Resource::File(dto.id),
+            ResourceTypeDto::Drive => Resource::Drive(dto.id),
         }
     }
 }
@@ -81,6 +83,7 @@ impl From<Resource> for ResourceDto {
         let (kind, id) = match r {
             Resource::Folder(id) => (ResourceTypeDto::Folder, id),
             Resource::File(id) => (ResourceTypeDto::File, id),
+            Resource::Drive(id) => (ResourceTypeDto::Drive, id),
         };
         ResourceDto { kind, id }
     }

src/application/dtos/mod.rs

@@ -6,6 +6,7 @@ pub mod calendar_dto;
 pub mod contact_dto;
 pub mod device_auth_dto;
 pub mod display_helpers;
+pub mod drive_dto;
 pub mod favorites_dto;
 pub mod file_dto;
 pub mod folder_dto;