feat: add shared_vehicle_ids schema and repository methods (refs #31)

- Add migration 004_add_shared_vehicle_ids.sql with UUID array column and GIN index
- Update DocumentRecord interface to include sharedVehicleIds field
- Add sharedVehicleIds to CreateDocumentBody and UpdateDocumentBody schemas
- Update repository mapDocumentRecord() to map shared_vehicle_ids from database
- Update insert() and batchInsert() to handle sharedVehicleIds
- Update updateMetadata() to support sharedVehicleIds updates
- Add addSharedVehicle() method using atomic array_append()
- Add removeSharedVehicle() method using atomic array_remove()
- Add listByVehicle() method to query by primary or shared vehicle

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

backend/src/features/documents/data/documents.repository.ts

@@ -28,6 +28,7 @@ export class DocumentsRepository {
       expirationDate: row.expiration_date,
       emailNotifications: row.email_notifications,
       scanForMaintenance: row.scan_for_maintenance,
+      sharedVehicleIds: row.shared_vehicle_ids || [],
       createdAt: row.created_at,
       updatedAt: row.updated_at,
       deletedAt: row.deleted_at
@@ -50,11 +51,12 @@ export class DocumentsRepository {
     expirationDate?: string | null;
     emailNotifications?: boolean;
     scanForMaintenance?: boolean;
+    sharedVehicleIds?: string[];
   }): Promise<DocumentRecord> {
     const res = await this.db.query(
       `INSERT INTO documents (
-        id, user_id, vehicle_id, document_type, title, notes, details, issued_date, expiration_date, email_notifications, scan_for_maintenance
-      ) VALUES ($1,$2,$3,$4,$5,$6,$7,$8,$9,$10,$11)
+        id, user_id, vehicle_id, document_type, title, notes, details, issued_date, expiration_date, email_notifications, scan_for_maintenance, shared_vehicle_ids
+      ) VALUES ($1,$2,$3,$4,$5,$6,$7,$8,$9,$10,$11,$12)
       RETURNING *`,
       [
         doc.id,
@@ -68,6 +70,7 @@ export class DocumentsRepository {
         doc.expirationDate ?? null,
         doc.emailNotifications ?? false,
         doc.scanForMaintenance ?? false,
+        doc.sharedVehicleIds ?? [],
       ]
     );
     return this.mapDocumentRecord(res.rows[0]);
@@ -103,6 +106,7 @@ export class DocumentsRepository {
       expirationDate?: string | null;
       emailNotifications?: boolean;
       scanForMaintenance?: boolean;
+      sharedVehicleIds?: string[];
     }>,
     client?: any
   ): Promise<DocumentRecord[]> {
@@ -128,17 +132,18 @@ export class DocumentsRepository {
         doc.issuedDate ?? null,
         doc.expirationDate ?? null,
         doc.emailNotifications ?? false,
-        doc.scanForMaintenance ?? false
+        doc.scanForMaintenance ?? false,
+        doc.sharedVehicleIds ?? []
       ];
 
-      const placeholder = `($${paramCount++}, $${paramCount++}, $${paramCount++}, $${paramCount++}, $${paramCount++}, $${paramCount++}, $${paramCount++}, $${paramCount++}, $${paramCount++}, $${paramCount++}, $${paramCount++})`;
+      const placeholder = `($${paramCount++}, $${paramCount++}, $${paramCount++}, $${paramCount++}, $${paramCount++}, $${paramCount++}, $${paramCount++}, $${paramCount++}, $${paramCount++}, $${paramCount++}, $${paramCount++}, $${paramCount++})`;
       placeholders.push(placeholder);
       values.push(...docParams);
     });
 
     const query = `
       INSERT INTO documents (
-        id, user_id, vehicle_id, document_type, title, notes, details, issued_date, expiration_date, email_notifications, scan_for_maintenance
+        id, user_id, vehicle_id, document_type, title, notes, details, issued_date, expiration_date, email_notifications, scan_for_maintenance, shared_vehicle_ids
       )
       VALUES ${placeholders.join(', ')}
       RETURNING *
@@ -152,7 +157,7 @@ export class DocumentsRepository {
     await this.db.query(`UPDATE documents SET deleted_at = NOW() WHERE id = $1 AND user_id = $2`, [id, userId]);
   }
 
-  async updateMetadata(id: string, userId: string, patch: Partial<Pick<DocumentRecord, 'title'|'notes'|'details'|'issuedDate'|'expirationDate'|'emailNotifications'|'scanForMaintenance'>>): Promise<DocumentRecord | null> {
+  async updateMetadata(id: string, userId: string, patch: Partial<Pick<DocumentRecord, 'title'|'notes'|'details'|'issuedDate'|'expirationDate'|'emailNotifications'|'scanForMaintenance'|'sharedVehicleIds'>>): Promise<DocumentRecord | null> {
     const fields: string[] = [];
     const params: any[] = [];
     let i = 1;
@@ -163,6 +168,7 @@ export class DocumentsRepository {
     if (patch.expirationDate !== undefined) { fields.push(`expiration_date = $${i++}`); params.push(patch.expirationDate); }
     if (patch.emailNotifications !== undefined) { fields.push(`email_notifications = $${i++}`); params.push(patch.emailNotifications); }
     if (patch.scanForMaintenance !== undefined) { fields.push(`scan_for_maintenance = $${i++}`); params.push(patch.scanForMaintenance); }
+    if (patch.sharedVehicleIds !== undefined) { fields.push(`shared_vehicle_ids = $${i++}`); params.push(patch.sharedVehicleIds); }
     if (!fields.length) return this.findById(id, userId);
     params.push(id, userId);
     const sql = `UPDATE documents SET ${fields.join(', ')} WHERE id = $${i++} AND user_id = $${i++} AND deleted_at IS NULL RETURNING *`;
@@ -187,5 +193,56 @@ export class DocumentsRepository {
     );
     return res.rows[0] ? this.mapDocumentRecord(res.rows[0]) : null;
   }
+
+  // ========================
+  // Shared Vehicle Operations (Atomic)
+  // ========================
+
+  /**
+   * Atomically add a vehicle to the shared_vehicle_ids array.
+   * Uses PostgreSQL array_append() to avoid race conditions.
+   */
+  async addSharedVehicle(docId: string, userId: string, vehicleId: string): Promise<DocumentRecord | null> {
+    const res = await this.db.query(
+      `UPDATE documents
+       SET shared_vehicle_ids = array_append(shared_vehicle_ids, $1::uuid)
+       WHERE id = $2 AND user_id = $3 AND deleted_at IS NULL
+         AND NOT ($1::uuid = ANY(shared_vehicle_ids))
+       RETURNING *`,
+      [vehicleId, docId, userId]
+    );
+    return res.rows[0] ? this.mapDocumentRecord(res.rows[0]) : null;
+  }
+
+  /**
+   * Atomically remove a vehicle from the shared_vehicle_ids array.
+   * Uses PostgreSQL array_remove() to avoid race conditions.
+   */
+  async removeSharedVehicle(docId: string, userId: string, vehicleId: string): Promise<DocumentRecord | null> {
+    const res = await this.db.query(
+      `UPDATE documents
+       SET shared_vehicle_ids = array_remove(shared_vehicle_ids, $1::uuid)
+       WHERE id = $2 AND user_id = $3 AND deleted_at IS NULL
+       RETURNING *`,
+      [vehicleId, docId, userId]
+    );
+    return res.rows[0] ? this.mapDocumentRecord(res.rows[0]) : null;
+  }
+
+  /**
+   * List all documents associated with a vehicle (either as primary or shared).
+   * Returns documents where vehicle_id = vehicleId OR vehicleId = ANY(shared_vehicle_ids).
+   */
+  async listByVehicle(userId: string, vehicleId: string): Promise<DocumentRecord[]> {
+    const res = await this.db.query(
+      `SELECT * FROM documents
+       WHERE user_id = $1
+         AND deleted_at IS NULL
+         AND (vehicle_id = $2 OR $2::uuid = ANY(shared_vehicle_ids))
+       ORDER BY created_at DESC`,
+      [userId, vehicleId]
+    );
+    return res.rows.map(row => this.mapDocumentRecord(row));
+  }
 }