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/package-lock.json

@@ -13,6 +13,7 @@
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       },
       "devDependencies": {
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         "@types/react": "18.3.12",
         "@types/react-dom": "18.3.1",
         "@vitejs/plugin-react": "4.3.4",
@@ -763,6 +764,22 @@
         "node": "^22.20 || ^24.12 || >=25"
       }
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+    "node_modules/@playwright/test": {
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+      "resolved": "https://registry.npmjs.org/@playwright/test/-/test-1.62.1.tgz",
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+      "dev": true,
+      "license": "Apache-2.0",
+      "dependencies": {
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+      },
+      "bin": {
+        "playwright": "cli.js"
+      },
+      "engines": {
+        "node": ">=20"
+      }
+    },
     "node_modules/@rollup/rollup-android-arm-eabi": {
       "version": "4.62.4",
       "resolved": "https://registry.npmjs.org/@rollup/rollup-android-arm-eabi/-/rollup-android-arm-eabi-4.62.4.tgz",
@@ -1543,6 +1560,53 @@
       "dev": true,
       "license": "ISC"
     },
+    "node_modules/playwright": {
+      "version": "1.62.1",
+      "resolved": "https://registry.npmjs.org/playwright/-/playwright-1.62.1.tgz",
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+      "dev": true,
+      "license": "Apache-2.0",
+      "dependencies": {
+        "playwright-core": "1.62.1"
+      },
+      "bin": {
+        "playwright": "cli.js"
+      },
+      "engines": {
+        "node": ">=20"
+      },
+      "optionalDependencies": {
+        "fsevents": "2.3.2"
+      }
+    },
+    "node_modules/playwright-core": {
+      "version": "1.62.1",
+      "resolved": "https://registry.npmjs.org/playwright-core/-/playwright-core-1.62.1.tgz",
+      "integrity": "sha512-wPYSwEBJY9GHraISXqyqtx0na0LpO3XEX7jNDhntbex7tzUS7kLnZsOlFruFJB4Hi/rhDMjXGqHewDZ68nYZVw==",
+      "dev": true,
+      "license": "Apache-2.0",
+      "bin": {
+        "playwright-core": "cli.js"
+      },
+      "engines": {
+        "node": ">=20"
+      }
+    },
+    "node_modules/playwright/node_modules/fsevents": {
+      "version": "2.3.2",
+      "resolved": "https://registry.npmjs.org/fsevents/-/fsevents-2.3.2.tgz",
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+      "dev": true,
+      "hasInstallScript": true,
+      "license": "MIT",
+      "optional": true,
+      "os": [
+        "darwin"
+      ],
+      "engines": {
+        "node": "^8.16.0 || ^10.6.0 || >=11.0.0"
+      }
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     "node_modules/postcss": {
       "version": "8.5.25",
       "resolved": "https://registry.npmjs.org/postcss/-/postcss-8.5.25.tgz",