feat(sim): F4.2 the sim protocol, the simulation room and LocalSimHost; M9 measured

packages/protocol holds the one list of /sim messages and checks every
field, naming what is wrong. packages/sim has the simulation room for F and
the web worker: the document's snapshot at start, the engine's clock on the
wall clock with Java's speed as cable delay, subscriptions to cable
activity, a card's new frames and a program's new window lines, capture and
clock kept over a stop, the command line as first action, a core failure
told to every client. LocalSimHost mirrors the document into the worker and
back without echo. M9 in Chromium: 17 examples give the same capture as in
Node, character for character; the room runs in a real worker.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

package-lock.json

@@ -10,7 +10,9 @@
         "packages/*"
       ],
       "devDependencies": {
+        "@playwright/test": "^1.62.1",
         "@types/node": "^20.19.0",
+        "esbuild": "^0.28.2",
         "typescript": "^5.9.0",
         "vitest": "^3.2.0"
       },
@@ -479,6 +481,14 @@
       "resolved": "packages/fls",
       "link": true
     },
+    "node_modules/@mdg-filius/protocol": {
+      "resolved": "packages/protocol",
+      "link": true
+    },
+    "node_modules/@mdg-filius/sim": {
+      "resolved": "packages/sim",
+      "link": true
+    },
     "node_modules/@napi-rs/lzma-linux-x64-gnu": {
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       "resolved": "https://registry.npmjs.org/@napi-rs/lzma-linux-x64-gnu/-/lzma-linux-x64-gnu-1.5.1.tgz",
@@ -496,6 +506,22 @@
         "node": "^22.20 || ^24.12 || >=25"
       }
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+    "node_modules/@playwright/test": {
+      "version": "1.62.1",
+      "resolved": "https://registry.npmjs.org/@playwright/test/-/test-1.62.1.tgz",
+      "integrity": "sha512-DTcUc8qii+cpHvtOwggMtBRMjKZHXYWdw8syRYu2vtzuq4Wxphqq4NfCs5Zt44L6mA8rfDfj+PHnxFc/FeK6mQ==",
+      "dev": true,
+      "license": "Apache-2.0",
+      "dependencies": {
+        "playwright": "1.62.1"
+      },
+      "bin": {
+        "playwright": "cli.js"
+      },
+      "engines": {
+        "node": ">=20"
+      }
+    },
     "node_modules/@rollup/rollup-android-arm-eabi": {
       "version": "4.63.5",
       "resolved": "https://registry.npmjs.org/@rollup/rollup-android-arm-eabi/-/rollup-android-arm-eabi-4.63.5.tgz",
@@ -1297,6 +1323,53 @@
         "url": "https://github.com/sponsors/jonschlinkert"
       }
     },
+    "node_modules/playwright": {
+      "version": "1.62.1",
+      "resolved": "https://registry.npmjs.org/playwright/-/playwright-1.62.1.tgz",
+      "integrity": "sha512-0M+L3LAD8/nm554LOla9Ayx0j0tmFZ0FBcoQ7F1VuVHpM/XpiC8RcDzBQB8W5+hA8L22THxELzeF+2WcUzvcLg==",
+      "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",
+      "integrity": "sha512-xiqMQR4xAeHTuB9uWm+fFRcIOgKBMiOBP+eXiyT7jsgVCq1bkVygt00oASowB7EdtpOHaaPgKt812P9ab+DDKA==",
+      "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": "8.5.28",
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@@ -1745,6 +1818,25 @@
         "fflate": "^0.8.2",
         "saxes": "^6.0.0"
       }
+    },
+    "packages/protocol": {
+      "name": "@mdg-filius/protocol",
+      "version": "0.0.0",
+      "license": "GPL-3.0-only",
+      "dependencies": {
+        "@mdg-filius/core": "0.0.0"
+      }
+    },
+    "packages/sim": {
+      "name": "@mdg-filius/sim",
+      "version": "0.0.0",
+      "license": "GPL-3.0-only",
+      "dependencies": {
+        "@mdg-filius/core": "0.0.0",
+        "@mdg-filius/doc": "0.0.0",
+        "@mdg-filius/protocol": "0.0.0",
+        "yjs": "^13.6.33"
+      }
     }
   }
 }