M7: portfolio polish and final acceptance

Automated migrations on container startup (backend/entrypoint.sh), scripted n8n workflow activation (make n8n-setup), Playwright E2E test covering the full 9-step demo script (verified passing against the live stack, including the previously-unverified 360px responsive layout), evidence screenshots of all main pages, architecture diagram, and artifacts/evidence/final-summary.md with commit/commands/test counts/RAGcore and n8n evidence/MCP sample calls/known limitations/portfolio wording. Verified the complete clean-checkout path from a genuinely wiped-volumes state: automatic migrations, seed, 66 backend tests passing, and a live S1 return round-tripped through a freshly-activated n8n instance. Added .gitattributes to force LF line endings on shell scripts, preventing a real cross-platform breakage of entrypoint.sh's shebang.

frontend/playwright.config.ts

@@ -0,0 +1,23 @@
+import { defineConfig, devices } from "@playwright/test";
+
+export default defineConfig({
+  testDir: "./e2e",
+  // _capture-screenshots.spec.ts is evidence-generation tooling, not a regression test —
+  // it mutates demo data via a reset and is run explicitly, not as part of the suite.
+  testIgnore: "**/_*.spec.ts",
+  timeout: 30_000,
+  fullyParallel: false,
+  workers: 1,
+  reporter: [["list"], ["html", { open: "never", outputFolder: "playwright-report" }]],
+  use: {
+    baseURL: process.env.MOBILITYOPS_PUBLIC_URL ?? "http://localhost:1228",
+    trace: "retain-on-failure",
+    screenshot: "only-on-failure",
+  },
+  projects: [
+    {
+      name: "chromium",
+      use: { ...devices["Desktop Chrome"] },
+    },
+  ],
+});