feat: named registers, X/Z reports, daily rollup, fix drawerSessionId

Registers:
- New register table with location association
- CRUD service + API routes (POST/GET/PATCH/DELETE /registers)
- Drawer sessions now link to a register via registerId
- Register ID persisted in localStorage per device

X/Z Reports:
- ReportService with getDrawerReport() (X or Z depending on session state)
- Z report auto-displayed on drawer close in the drawer dialog
- X report (Current Shift Report) button on open drawer view
- Report shows: sales summary, payment breakdown, discounts, cash accountability, adjustments

Daily Rollup:
- ReportService.getDailyReport() aggregates all sessions at a location for a date
- New /reports/daily endpoint with locationId + date params
- Frontend daily report page with date picker, location selector, session breakdown

Critical Fix:
- drawerSessionId is now populated on transactions when completing (was never set before)
- This enables accurate per-drawer reporting and cash accountability

Migration 0044: register table, drawer_session.register_id column

Tests: 14 new (register CRUD, drawer report X/Z, drawerSessionId population, daily rollup, register-drawer link)
Full suite: 367 passed

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

packages/backend/src/services/register.service.ts

@@ -0,0 +1,84 @@
+import { eq, and, count, type Column } from 'drizzle-orm'
+import type { PostgresJsDatabase } from 'drizzle-orm/postgres-js'
+import { registers } from '../db/schema/pos.js'
+import { NotFoundError } from '../lib/errors.js'
+import type { RegisterCreateInput, RegisterUpdateInput, PaginationInput } from '@lunarfront/shared/schemas'
+import { withPagination, withSort, buildSearchCondition, paginatedResponse } from '../utils/pagination.js'
+
+export const RegisterService = {
+  async create(db: PostgresJsDatabase<any>, input: RegisterCreateInput) {
+    const [register] = await db
+      .insert(registers)
+      .values({
+        locationId: input.locationId,
+        name: input.name,
+      })
+      .returning()
+    return register
+  },
+
+  async getById(db: PostgresJsDatabase<any>, id: string) {
+    const [register] = await db
+      .select()
+      .from(registers)
+      .where(eq(registers.id, id))
+      .limit(1)
+    return register ?? null
+  },
+
+  async list(db: PostgresJsDatabase<any>, params: PaginationInput, filters?: { locationId?: string }) {
+    const conditions = [eq(registers.isActive, true)]
+
+    if (params.q) {
+      conditions.push(buildSearchCondition(params.q, [registers.name])!)
+    }
+    if (filters?.locationId) {
+      conditions.push(eq(registers.locationId, filters.locationId))
+    }
+
+    const where = conditions.length === 1 ? conditions[0] : and(...conditions)
+
+    const sortableColumns: Record<string, Column> = {
+      name: registers.name,
+      created_at: registers.createdAt,
+    }
+
+    let query = db.select().from(registers).where(where).$dynamic()
+    query = withSort(query, params.sort, params.order, sortableColumns, registers.name)
+    query = withPagination(query, params.page, params.limit)
+
+    const [data, [{ total }]] = await Promise.all([
+      query,
+      db.select({ total: count() }).from(registers).where(where),
+    ])
+
+    return paginatedResponse(data, total, params.page, params.limit)
+  },
+
+  async listAll(db: PostgresJsDatabase<any>, locationId?: string) {
+    const conditions = [eq(registers.isActive, true)]
+    if (locationId) conditions.push(eq(registers.locationId, locationId))
+    const where = conditions.length === 1 ? conditions[0] : and(...conditions)
+    return db.select().from(registers).where(where)
+  },
+
+  async update(db: PostgresJsDatabase<any>, id: string, input: RegisterUpdateInput) {
+    const [updated] = await db
+      .update(registers)
+      .set({ ...input, updatedAt: new Date() })
+      .where(eq(registers.id, id))
+      .returning()
+    if (!updated) throw new NotFoundError('Register')
+    return updated
+  },
+
+  async delete(db: PostgresJsDatabase<any>, id: string) {
+    const [deleted] = await db
+      .update(registers)
+      .set({ isActive: false, updatedAt: new Date() })
+      .where(eq(registers.id, id))
+      .returning()
+    if (!deleted) throw new NotFoundError('Register')
+    return deleted
+  },
+}