Scaffold arrangement demo slice with CompareBar wiring

Add a self-contained demo build target for the Providers → Packages →
Comparison flow, deployable as a static SPA at /arrangement/.

- vite.demo.config.ts: per-slice build via --mode, base path flips for
  dev vs prod, output to dist-demo/<slice>/
- src/demo/: shared fixtures (7 providers across verified/tier3/tier2
  with real venue photography from brandassets) + Zustand basket store
  with ?compare= URL persistence
- Verified-provider packages now share the nine canonical Essentials
  line items per FA convention; only Optionals/Extras vary
- App-level CompareBar surfaces "Already added" / "Maximum 3" feedback
  via transient store error
- ProviderCard logo objectFit cover→contain so wide logos don't crop
- npm scripts demo:dev / demo:build, deps zustand + react-router-dom

package-lock.json

@@ -14,7 +14,9 @@
         "@mui/material": "^5.16.0",
         "@mui/system": "^5.16.0",
         "react": "^18.3.0",
-        "react-dom": "^18.3.0"
+        "react-dom": "^18.3.0",
+        "react-router-dom": "^7.14.1",
+        "zustand": "^5.0.12"
       },
       "devDependencies": {
         "@eslint/js": "^9.39.4",
@@ -5387,6 +5389,19 @@
       "integrity": "sha512-ASFBup0Mz1uyiIjANan1jzLQami9z1PoYSZCiiYW2FczPbenXc45FZdBZLzOT+r6+iciuEModtmCti+hjaAk0A==",
       "license": "MIT"
     },
+    "node_modules/cookie": {
+      "version": "1.1.1",
+      "resolved": "https://registry.npmjs.org/cookie/-/cookie-1.1.1.tgz",
+      "integrity": "sha512-ei8Aos7ja0weRpFzJnEA9UHJ/7XQmqglbRwnf2ATjcB9Wq874VKH9kfjjirM6UhU2/E5fFYadylyhFldcqSidQ==",
+      "license": "MIT",
+      "engines": {
+        "node": ">=18"
+      },
+      "funding": {
+        "type": "opencollective",
+        "url": "https://opencollective.com/express"
+      }
+    },
     "node_modules/cosmiconfig": {
       "version": "7.1.0",
       "resolved": "https://registry.npmjs.org/cosmiconfig/-/cosmiconfig-7.1.0.tgz",
@@ -9530,6 +9545,44 @@
         "node": ">=0.10.0"
       }
     },
+    "node_modules/react-router": {
+      "version": "7.14.1",
+      "resolved": "https://registry.npmjs.org/react-router/-/react-router-7.14.1.tgz",
+      "integrity": "sha512-5BCvFskyAAVumqhEKh/iPhLOIkfxcEUz8WqFIARCkMg8hZZzDYX9CtwxXA0e+qT8zAxmMC0x3Ckb9iMONwc5jg==",
+      "license": "MIT",
+      "dependencies": {
+        "cookie": "^1.0.1",
+        "set-cookie-parser": "^2.6.0"
+      },
+      "engines": {
+        "node": ">=20.0.0"
+      },
+      "peerDependencies": {
+        "react": ">=18",
+        "react-dom": ">=18"
+      },
+      "peerDependenciesMeta": {
+        "react-dom": {
+          "optional": true
+        }
+      }
+    },
+    "node_modules/react-router-dom": {
+      "version": "7.14.1",
+      "resolved": "https://registry.npmjs.org/react-router-dom/-/react-router-dom-7.14.1.tgz",
+      "integrity": "sha512-ZkrQuwwhGibjQLqH1eCdyiZyLWglPxzxdl5tgwgKEyCSGC76vmAjleGocRe3J/MLfzMUIKwaFJWpFVJhK3d2xA==",
+      "license": "MIT",
+      "dependencies": {
+        "react-router": "7.14.1"
+      },
+      "engines": {
+        "node": ">=20.0.0"
+      },
+      "peerDependencies": {
+        "react": ">=18",
+        "react-dom": ">=18"
+      }
+    },
     "node_modules/react-transition-group": {
       "version": "4.4.5",
       "resolved": "https://registry.npmjs.org/react-transition-group/-/react-transition-group-4.4.5.tgz",
@@ -9901,6 +9954,12 @@
         "semver": "bin/semver.js"
       }
     },
+    "node_modules/set-cookie-parser": {
+      "version": "2.7.2",
+      "resolved": "https://registry.npmjs.org/set-cookie-parser/-/set-cookie-parser-2.7.2.tgz",
+      "integrity": "sha512-oeM1lpU/UvhTxw+g3cIfxXHyJRc/uidd3yK1P242gzHds0udQBYzs3y8j4gCCW+ZJ7ad0yctld8RYO+bdurlvw==",
+      "license": "MIT"
+    },
     "node_modules/set-function-length": {
       "version": "1.2.2",
       "resolved": "https://registry.npmjs.org/set-function-length/-/set-function-length-1.2.2.tgz",
@@ -12099,6 +12158,35 @@
       "peerDependencies": {
         "zod": "^3.25.0 || ^4.0.0"
       }
+    },
+    "node_modules/zustand": {
+      "version": "5.0.12",
+      "resolved": "https://registry.npmjs.org/zustand/-/zustand-5.0.12.tgz",
+      "integrity": "sha512-i77ae3aZq4dhMlRhJVCYgMLKuSiZAaUPAct2AksxQ+gOtimhGMdXljRT21P5BNpeT4kXlLIckvkPM029OljD7g==",
+      "license": "MIT",
+      "engines": {
+        "node": ">=12.20.0"
+      },
+      "peerDependencies": {
+        "@types/react": ">=18.0.0",
+        "immer": ">=9.0.6",
+        "react": ">=18.0.0",
+        "use-sync-external-store": ">=1.2.0"
+      },
+      "peerDependenciesMeta": {
+        "@types/react": {
+          "optional": true
+        },
+        "immer": {
+          "optional": true
+        },
+        "react": {
+          "optional": true
+        },
+        "use-sync-external-store": {
+          "optional": true
+        }
+      }
     }
   }
 }