test: add full-stack Playwright integration test infrastructure

Sprint 12 Phase 2: Real integration tests with seed DB
- R__seed_test_data.sql (Flyway repeatable, 7 members, strains, batches, docs, board, events)
- TestResetController (profile-gated per-test DB reset)
- docker-compose.test.yml (self-contained, tmpfs Postgres)
- Dockerfile.playwright (v1.60.0, pre-installed deps)
- 13 integration spec files, 70+ test cases (@smoke + @full)
- seed-constants.ts, selectors.ts, api-client.ts test helpers

cannamanage-frontend/e2e/integration/04-distributions.spec.ts

@@ -0,0 +1,59 @@
+import { expect, test } from "@playwright/test"
+
+import { ApiClient } from "../api-client"
+import { SEED } from "../seed-constants"
+import { SEL } from "../selectors"
+
+const apiClient = new ApiClient()
+
+test.describe("Distributions Page @smoke", () => {
+  test.beforeEach(async () => {
+    await apiClient.login(SEED.admin.email, SEED.admin.password)
+    await apiClient.resetDb()
+  })
+
+  test("displays recent distributions from seed", async ({ page }) => {
+    await page.goto("/distributions")
+    // Verify distributions table/list is visible
+    await expect(
+      page.locator(SEL.distributions.table).or(page.getByRole("table"))
+    ).toBeVisible()
+  })
+
+  test("date filter works", async ({ page }) => {
+    await page.goto("/distributions")
+
+    // Look for filter buttons/tabs for today/week/month/all
+    const todayFilter = page.getByRole("button", { name: /heute|today/i })
+    const allFilter = page.getByRole("button", { name: /alle|all/i })
+
+    if (await todayFilter.isVisible()) {
+      await todayFilter.click()
+      // Page should update (no error)
+      await expect(page.locator("body")).toBeVisible()
+    }
+
+    if (await allFilter.isVisible()) {
+      await allFilter.click()
+      await expect(page.locator("body")).toBeVisible()
+    }
+  })
+
+  test("new distribution button navigates to form", async ({ page }) => {
+    await page.goto("/distributions")
+    const newBtn = page
+      .locator(SEL.distributions.newButton)
+      .or(page.getByRole("link", { name: /neue ausgabe|new/i }))
+    await expect(newBtn).toBeVisible()
+    await newBtn.click()
+    await page.waitForURL(/\/distributions\/new/)
+  })
+
+  test("shows gram total display", async ({ page }) => {
+    await page.goto("/distributions")
+    // The page should show some kind of total/summary
+    await expect(
+      page.getByText(/gramm|gesamt|total/i).first()
+    ).toBeVisible()
+  })
+})