fix(app): add Vite dev workflow, fix onLayout prop, fix icon path, allow Google Fonts CSP

The v5.0.0 React UI redesign shipped without a working dev workflow —
`npm start` only ran `electron .` which loaded the source index.html
that references raw .tsx files. The browser couldn't execute them, so
the app rendered an empty #root and the user saw 'lot of errors'.

This commit restores a real dev workflow:

1. **Vite dev server wired into npm scripts** — added `concurrently`
   + `wait-on` as devDeps. `npm run dev` now runs Vite (port 5173)
   and Electron together with `wait-on tcp:5173` so Electron only
   starts after the dev server is ready.

2. **Main process loads Vite URL in dev, dist/ in prod** — window
   module now checks `process.env.VITE_DEV_SERVER_URL` and
   `app.isPackaged` to decide what to load. Production still
   loads the built `dist/renderer/index.html`.

3. **Fixed ReferenceError: app is not defined** — window module
   referenced `app.isPackaged` but only imported `BrowserWindow`.
   Added `app` to the destructured import.

4. **Fixed wrong icon path** — window creation used
   `../../assets/icon.png` from src/main/window/ which resolved
   to `src/assets/icon.png` (doesn't exist). Icon lives at
   project root, so path is now `../../../assets/icon.png`.

5. **Allowed Google Fonts in CSP** — the strict CSP
   (`font-src 'self' data:`, `connect-src 'self'`) blocked
   the preconnect/css link to fonts.googleapis.com / .gstatic.com.
   Added both domains so Plus Jakarta Sans loads.

6. **Renamed onLayout → onLayoutChange** in AppShell — react-resizable-panels
   v4 renamed the prop. The v1 name was being spread to a DOM
   div and React logged 'Unknown event handler property' warnings.
   Test mock updated for parity.

7. **show: false → show: true** — ready-to-show was hanging on
   this Wayland/container combo. Now the window is shown
   immediately on create.

Verified end-to-end:
- 305/305 vitest tests pass
- Vite dev server starts on :5173
- Electron loads localhost:5173 and React mounts
- Header 'MarkdownConverter' + sidebar with 'No files open' visible
- No onLayout warnings after HMR
- All blocked errors resolved

package-lock.json

@@ -1,12 +1,12 @@
 {
   "name": "markdown-converter",
-  "version": "4.4.2",
+  "version": "5.0.0",
   "lockfileVersion": 3,
   "requires": true,
   "packages": {
     "": {
       "name": "markdown-converter",
-      "version": "4.4.2",
+      "version": "5.0.0",
       "license": "MIT",
       "dependencies": {
         "@codemirror/autocomplete": "^6.20.1",
@@ -86,6 +86,7 @@
         "autoprefixer": "^10.5.0",
         "class-variance-authority": "^0.7.1",
         "clsx": "^2.1.1",
+        "concurrently": "^10.0.3",
         "cross-env": "^10.0.0",
         "electron": "^41.1.1",
         "electron-builder": "^26.0.12",
@@ -104,7 +105,8 @@
         "tailwindcss-animate": "^1.0.7",
         "typescript": "^6.0.3",
         "vite": "^8.0.16",
-        "vitest": "^4.1.8"
+        "vitest": "^4.1.8",
+        "wait-on": "^9.0.10"
       }
     },
     "node_modules/@adobe/css-tools": {
@@ -1902,6 +1904,60 @@
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       "license": "MIT"
     },
+    "node_modules/@hapi/address": {
+      "version": "5.1.1",
+      "resolved": "https://registry.npmjs.org/@hapi/address/-/address-5.1.1.tgz",
+      "integrity": "sha512-A+po2d/dVoY7cYajycYI43ZbYMXukuopIsqCjh5QzsBCipDtdofHntljDlpccMjIfTy6UOkg+5KPriwYch2bXA==",
+      "dev": true,
+      "license": "BSD-3-Clause",
+      "dependencies": {
+        "@hapi/hoek": "^11.0.2"
+      },
+      "engines": {
+        "node": ">=14.0.0"
+      }
+    },
+    "node_modules/@hapi/formula": {
+      "version": "3.0.2",
+      "resolved": "https://registry.npmjs.org/@hapi/formula/-/formula-3.0.2.tgz",
+      "integrity": "sha512-hY5YPNXzw1He7s0iqkRQi+uMGh383CGdyyIGYtB+W5N3KHPXoqychklvHhKCC9M3Xtv0OCs/IHw+r4dcHtBYWw==",
+      "dev": true,
+      "license": "BSD-3-Clause"
+    },
+    "node_modules/@hapi/hoek": {
+      "version": "11.0.7",
+      "resolved": "https://registry.npmjs.org/@hapi/hoek/-/hoek-11.0.7.tgz",
+      "integrity": "sha512-HV5undWkKzcB4RZUusqOpcgxOaq6VOAH7zhhIr2g3G8NF/MlFO75SjOr2NfuSx0Mh40+1FqCkagKLJRykUWoFQ==",
+      "dev": true,
+      "license": "BSD-3-Clause"
+    },
+    "node_modules/@hapi/pinpoint": {
+      "version": "2.0.1",
+      "resolved": "https://registry.npmjs.org/@hapi/pinpoint/-/pinpoint-2.0.1.tgz",
+      "integrity": "sha512-EKQmr16tM8s16vTT3cA5L0kZZcTMU5DUOZTuvpnY738m+jyP3JIUj+Mm1xc1rsLkGBQ/gVnfKYPwOmPg1tUR4Q==",
+      "dev": true,
+      "license": "BSD-3-Clause"
+    },
+    "node_modules/@hapi/tlds": {
+      "version": "1.1.6",
+      "resolved": "https://registry.npmjs.org/@hapi/tlds/-/tlds-1.1.6.tgz",
+      "integrity": "sha512-xdi7A/4NZokvV0ewovme3aUO5kQhW9pQ2YD1hRqZGhhSi5rBv4usHYidVocXSi9eihYsznZxLtAiEYYUL6VBGw==",
+      "dev": true,
+      "license": "BSD-3-Clause",
+      "engines": {
+        "node": ">=14.0.0"
+      }
+    },
+    "node_modules/@hapi/topo": {
+      "version": "6.0.2",
+      "resolved": "https://registry.npmjs.org/@hapi/topo/-/topo-6.0.2.tgz",
+      "integrity": "sha512-KR3rD5inZbGMrHmgPxsJ9dbi6zEK+C3ZwUwTa+eMwWLz7oijWUTWD2pMSNNYJAU6Qq+65NkxXjqHr/7LM2Xkqg==",
+      "dev": true,
+      "license": "BSD-3-Clause",
+      "dependencies": {
+        "@hapi/hoek": "^11.0.2"
+      }
+    },
     "node_modules/@hookform/resolvers": {
       "version": "5.4.0",
       "resolved": "https://registry.npmjs.org/@hookform/resolvers/-/resolvers-5.4.0.tgz",
@@ -6982,6 +7038,46 @@
         "postcss": "^8.1.0"
       }
     },
+    "node_modules/axios": {
+      "version": "1.17.0",
+      "resolved": "https://registry.npmjs.org/axios/-/axios-1.17.0.tgz",
+      "integrity": "sha512-J8SwNxprqqpbfenehxWYXE7CW+wM1BB4w3+N+g+/Wx40xM4rsLrfPmHHxSWIxJLYDgSY/HqlFPIYb2/S3rxafw==",
+      "dev": true,
+      "license": "MIT",
+      "dependencies": {
+        "follow-redirects": "^1.16.0",
+        "form-data": "^4.0.5",
+        "https-proxy-agent": "^5.0.1",
+        "proxy-from-env": "^2.1.0"
+      }
+    },
+    "node_modules/axios/node_modules/agent-base": {
+      "version": "6.0.2",
+      "resolved": "https://registry.npmjs.org/agent-base/-/agent-base-6.0.2.tgz",
+      "integrity": "sha512-RZNwNclF7+MS/8bDg70amg32dyeZGZxiDuQmZxKLAlQjr3jGyLx+4Kkk58UO7D2QdgFIQCovuSuZESne6RG6XQ==",
+      "dev": true,
+      "license": "MIT",
+      "dependencies": {
+        "debug": "4"
+      },
+      "engines": {
+        "node": ">= 6.0.0"
+      }
+    },
+    "node_modules/axios/node_modules/https-proxy-agent": {
+      "version": "5.0.1",
+      "resolved": "https://registry.npmjs.org/https-proxy-agent/-/https-proxy-agent-5.0.1.tgz",
+      "integrity": "sha512-dFcAjpTQFgoLMzC2VwU+C/CbS7uRL0lWmxDITmqm7C+7F0Odmj6s9l6alZc6AELXhrnggM2CeWSXHGOdX2YtwA==",
+      "dev": true,
+      "license": "MIT",
+      "dependencies": {
+        "agent-base": "6",
+        "debug": "4"
+      },
+      "engines": {
+        "node": ">= 6"
+      }
+    },
     "node_modules/babel-jest": {
       "version": "30.3.0",
       "resolved": "https://registry.npmjs.org/babel-jest/-/babel-jest-30.3.0.tgz",
@@ -7889,6 +7985,185 @@
         "typedarray": "^0.0.6"
       }
     },
+    "node_modules/concurrently": {
+      "version": "10.0.3",
+      "resolved": "https://registry.npmjs.org/concurrently/-/concurrently-10.0.3.tgz",
+      "integrity": "sha512-hc3LH4UaKWd/bbyDK/IGVa4RB6PtQ3CUYwtrkzqHn+wIG3Hr5fhpRlk0L/gCa8ZE1L/Ufj50Zho69cI5w8SQBA==",
+      "dev": true,
+      "license": "MIT",
+      "dependencies": {
+        "chalk": "5.6.2",
+        "rxjs": "7.8.2",
+        "shell-quote": "1.8.4",
+        "supports-color": "10.2.2",
+        "tree-kill": "1.2.2",
+        "yargs": "18.0.0"
+      },
+      "bin": {
+        "conc": "dist/bin/index.js",
+        "concurrently": "dist/bin/index.js"
+      },
+      "engines": {
+        "node": ">=22"
+      },
+      "funding": {
+        "url": "https://github.com/open-cli-tools/concurrently?sponsor=1"
+      }
+    },
+    "node_modules/concurrently/node_modules/ansi-regex": {
+      "version": "6.2.2",
+      "resolved": "https://registry.npmjs.org/ansi-regex/-/ansi-regex-6.2.2.tgz",
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+      "license": "MIT",
+      "engines": {
+        "node": ">=12"
+      },
+      "funding": {
+        "url": "https://github.com/chalk/ansi-regex?sponsor=1"
+      }
+    },
+    "node_modules/concurrently/node_modules/ansi-styles": {
+      "version": "6.2.3",
+      "resolved": "https://registry.npmjs.org/ansi-styles/-/ansi-styles-6.2.3.tgz",
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+      "funding": {
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+      }
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+      "license": "ISC",
+      "dependencies": {
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+        "strip-ansi": "^7.1.0",
+        "wrap-ansi": "^9.0.0"
+      },
+      "engines": {
+        "node": ">=20"
+      }
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+      "dependencies": {
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+      },
+      "funding": {
+        "url": "https://github.com/chalk/strip-ansi?sponsor=1"
+      }
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+      "dev": true,
+      "license": "MIT",
+      "engines": {
+        "node": ">=18"
+      },
+      "funding": {
+        "url": "https://github.com/chalk/supports-color?sponsor=1"
+      }
+    },
+    "node_modules/concurrently/node_modules/wrap-ansi": {
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+      "dev": true,
+      "license": "MIT",
+      "dependencies": {
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+        "string-width": "^7.0.0",
+        "strip-ansi": "^7.1.0"
+      },
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+        "node": ">=18"
+      },
+      "funding": {
+        "url": "https://github.com/chalk/wrap-ansi?sponsor=1"
+      }
+    },
+    "node_modules/concurrently/node_modules/yargs": {
+      "version": "18.0.0",
+      "resolved": "https://registry.npmjs.org/yargs/-/yargs-18.0.0.tgz",
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+      "dev": true,
+      "license": "MIT",
+      "dependencies": {
+        "cliui": "^9.0.1",
+        "escalade": "^3.1.1",
+        "get-caller-file": "^2.0.5",
+        "string-width": "^7.2.0",
+        "y18n": "^5.0.5",
+        "yargs-parser": "^22.0.0"
+      },
+      "engines": {
+        "node": "^20.19.0 || ^22.12.0 || >=23"
+      }
+    },
+    "node_modules/concurrently/node_modules/yargs-parser": {
+      "version": "22.0.0",
+      "resolved": "https://registry.npmjs.org/yargs-parser/-/yargs-parser-22.0.0.tgz",
+      "integrity": "sha512-rwu/ClNdSMpkSrUb+d6BRsSkLUq1fmfsY6TOpYzTwvwkg1/NRG85KBy3kq++A8LKQwX6lsu+aWad+2khvuXrqw==",
+      "dev": true,
+      "license": "ISC",
+      "engines": {
+        "node": "^20.19.0 || ^22.12.0 || >=23"
+      }
+    },
     "node_modules/conf": {
       "version": "14.0.0",
       "resolved": "https://registry.npmjs.org/conf/-/conf-14.0.0.tgz",
@@ -10378,6 +10653,27 @@
       "dev": true,
       "license": "ISC"
     },
+    "node_modules/follow-redirects": {
+      "version": "1.16.0",
+      "resolved": "https://registry.npmjs.org/follow-redirects/-/follow-redirects-1.16.0.tgz",
+      "integrity": "sha512-y5rN/uOsadFT/JfYwhxRS5R7Qce+g3zG97+JrtFZlC9klX/W5hD7iiLzScI4nZqUS7DNUdhPgw4xI8W2LuXlUw==",
+      "dev": true,
+      "funding": [
+        {
+          "type": "individual",
+          "url": "https://github.com/sponsors/RubenVerborgh"
+        }
+      ],
+      "license": "MIT",
+      "engines": {
+        "node": ">=4.0"
+      },
+      "peerDependenciesMeta": {
+        "debug": {
+          "optional": true
+        }
+      }
+    },
     "node_modules/fontkit": {
       "version": "2.0.4",
       "resolved": "https://registry.npmjs.org/fontkit/-/fontkit-2.0.4.tgz",
@@ -10563,6 +10859,19 @@
         "node": "6.* || 8.* || >= 10.*"
       }
     },
+    "node_modules/get-east-asian-width": {
+      "version": "1.6.0",
+      "resolved": "https://registry.npmjs.org/get-east-asian-width/-/get-east-asian-width-1.6.0.tgz",
+      "integrity": "sha512-QRbvDIbx6YklUe6RxeTeleMR0yv3cYH6PsPZHcnVn7xv7zO1BHN8r0XETu8n6Ye3Q+ahtSarc3WgtNWmehIBfA==",
+      "dev": true,
+      "license": "MIT",
+      "engines": {
+        "node": ">=18"
+      },
+      "funding": {
+        "url": "https://github.com/sponsors/sindresorhus"
+      }
+    },
     "node_modules/get-intrinsic": {
       "version": "1.3.0",
       "resolved": "https://registry.npmjs.org/get-intrinsic/-/get-intrinsic-1.3.0.tgz",
@@ -12696,6 +13005,25 @@
         "jiti": "lib/jiti-cli.mjs"
       }
     },
+    "node_modules/joi": {
+      "version": "18.2.1",
+      "resolved": "https://registry.npmjs.org/joi/-/joi-18.2.1.tgz",
+      "integrity": "sha512-2/OKlogiESf2Nh3TFCrRjrr9z1DRHeW0I+KReF67+4J0Ns+8hBtHRmoWAZ2OFU6I5+TWLEe6sVlSdXPjHm5UbQ==",
+      "dev": true,
+      "license": "BSD-3-Clause",
+      "dependencies": {
+        "@hapi/address": "^5.1.1",
+        "@hapi/formula": "^3.0.2",
+        "@hapi/hoek": "^11.0.7",
+        "@hapi/pinpoint": "^2.0.1",
+        "@hapi/tlds": "^1.1.1",
+        "@hapi/topo": "^6.0.2",
+        "@standard-schema/spec": "^1.1.0"
+      },
+      "engines": {
+        "node": ">= 20"
+      }
+    },
     "node_modules/jpeg-exif": {
       "version": "1.1.4",
       "resolved": "https://registry.npmjs.org/jpeg-exif/-/jpeg-exif-1.1.4.tgz",
@@ -15183,6 +15511,16 @@
         "signal-exit": "^3.0.2"
       }
     },
+    "node_modules/proxy-from-env": {
+      "version": "2.1.0",
+      "resolved": "https://registry.npmjs.org/proxy-from-env/-/proxy-from-env-2.1.0.tgz",
+      "integrity": "sha512-cJ+oHTW1VAEa8cJslgmUZrc+sjRKgAKl3Zyse6+PV38hZe/V6Z14TbCuXcan9F9ghlz4QrFr2c92TNF82UkYHA==",
+      "dev": true,
+      "license": "MIT",
+      "engines": {
+        "node": ">=10"
+      }
+    },
     "node_modules/pump": {
       "version": "3.0.4",
       "resolved": "https://registry.npmjs.org/pump/-/pump-3.0.4.tgz",
@@ -15758,6 +16096,16 @@
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       "license": "BSD-3-Clause"
     },
+    "node_modules/rxjs": {
+      "version": "7.8.2",
+      "resolved": "https://registry.npmjs.org/rxjs/-/rxjs-7.8.2.tgz",
+      "integrity": "sha512-dhKf903U/PQZY6boNNtAGdWbG85WAbjT/1xYoZIC7FAY0yWapOBQVsVrDl58W86//e1VpMNBtRV4MaXfdMySFA==",
+      "dev": true,
+      "license": "Apache-2.0",
+      "dependencies": {
+        "tslib": "^2.1.0"
+      }
+    },
     "node_modules/safe-buffer": {
       "version": "5.2.1",
       "resolved": "https://registry.npmjs.org/safe-buffer/-/safe-buffer-5.2.1.tgz",
@@ -15958,6 +16306,19 @@
         "node": ">=8"
       }
     },
+    "node_modules/shell-quote": {
+      "version": "1.8.4",
+      "resolved": "https://registry.npmjs.org/shell-quote/-/shell-quote-1.8.4.tgz",
+      "integrity": "sha512-VsC6n6vz1ihYYyZZwX7YZSF5l5x36ca17OC+a69h94YqB7X6XLwf+5MOgynYir2SLFUbl8gIYvBo8K8RoNQ6bQ==",
+      "dev": true,
+      "license": "MIT",
+      "engines": {
+        "node": ">= 0.4"
+      },
+      "funding": {
+        "url": "https://github.com/sponsors/ljharb"
+      }
+    },
     "node_modules/siginfo": {
       "version": "2.0.0",
       "resolved": "https://registry.npmjs.org/siginfo/-/siginfo-2.0.0.tgz",
@@ -16878,6 +17239,16 @@
         "node": ">=20"
       }
     },
+    "node_modules/tree-kill": {
+      "version": "1.2.2",
+      "resolved": "https://registry.npmjs.org/tree-kill/-/tree-kill-1.2.2.tgz",
+      "integrity": "sha512-L0Orpi8qGpRG//Nd+H90vFB+3iHnue1zSSGmNOOCh1GLJ7rUKVwV2HvijphGQS2UmhUZewS9VgvxYIdgr+fG1A==",
+      "dev": true,
+      "license": "MIT",
+      "bin": {
+        "tree-kill": "cli.js"
+      }
+    },
     "node_modules/truncate-utf8-bytes": {
       "version": "1.0.2",
       "resolved": "https://registry.npmjs.org/truncate-utf8-bytes/-/truncate-utf8-bytes-1.0.2.tgz",
@@ -17441,6 +17812,26 @@
         "node": ">=18"
       }
     },
+    "node_modules/wait-on": {
+      "version": "9.0.10",
+      "resolved": "https://registry.npmjs.org/wait-on/-/wait-on-9.0.10.tgz",
+      "integrity": "sha512-rCoJEhvMr0X6alHmwc9abbrA5ZrLZFKpFQVKPNFwl2h7DapXOGdmimIHDtLOWhT4PjhZhxFEtZoQgEXbkDWdZw==",
+      "dev": true,
+      "license": "MIT",
+      "dependencies": {
+        "axios": "^1.16.0",
+        "joi": "^18.2.1",
+        "lodash": "^4.18.1",
+        "minimist": "^1.2.8",
+        "rxjs": "^7.8.2"
+      },
+      "bin": {
+        "wait-on": "bin/wait-on"
+      },
+      "engines": {
+        "node": ">=20.0.0"
+      }
+    },
     "node_modules/walker": {
       "version": "1.0.8",
       "resolved": "https://registry.npmjs.org/walker/-/walker-1.0.8.tgz",

package.json

@@ -5,6 +5,11 @@
   "main": "src/main/index.js",
   "scripts": {
     "start": "electron .",
+    "dev:renderer": "vite --config vite.renderer.config.ts",
+    "dev:electron": "wait-on tcp:5173 && cross-env VITE_DEV_SERVER_URL=http://localhost:5173 electron . -- --disable-gpu --disable-software-rasterizer --disable-dev-shm-usage",
+    "dev": "concurrently -k -n vite,electron -c blue,green \"npm:dev:renderer\" \"npm:dev:electron\"",
+    "build:renderer": "vite build --config vite.renderer.config.ts",
+    "preview": "npm run build:renderer && electron .",
     "test": "jest",
     "test:watch": "jest --watch",
     "test:coverage": "jest --coverage",
@@ -60,6 +65,7 @@
     "autoprefixer": "^10.5.0",
     "class-variance-authority": "^0.7.1",
     "clsx": "^2.1.1",
+    "concurrently": "^10.0.3",
     "cross-env": "^10.0.0",
     "electron": "^41.1.1",
     "electron-builder": "^26.0.12",
@@ -78,7 +84,8 @@
     "tailwindcss-animate": "^1.0.7",
     "typescript": "^6.0.3",
     "vite": "^8.0.16",
-    "vitest": "^4.1.8"
+    "vitest": "^4.1.8",
+    "wait-on": "^9.0.10"
   },
   "dependencies": {
     "@codemirror/autocomplete": "^6.20.1",

src/main/window/index.js

@@ -1,8 +1,9 @@
 // src/main/window/index.js
 // Main window creation
 
-const { BrowserWindow } = require('electron');
+const { app, BrowserWindow } = require('electron');
 const path = require('path');
+const fs = require('fs');
 const state = require('./state');
 const menu = require('../menu');
 
@@ -13,16 +14,28 @@ function createMainWindow() {
     height: bounds.height,
     x: bounds.x,
     y: bounds.y,
-    show: false,
+    show: true,
     webPreferences: {
       nodeIntegration: true,
       contextIsolation: false,
       spellcheck: true
     },
-    icon: path.join(__dirname, '../../assets/icon.png')
+    icon: path.join(__dirname, '../../../assets/icon.png')
   });
 
-  win.loadFile(path.join(__dirname, '../../renderer/index.html'));
+  // Dev (Vite): load the running dev server so .tsx is transformed on the fly.
+  // Production: load the built dist/renderer/index.html (Vite output).
+  // VITE_DEV_SERVER_URL is set by `npm run dev` via cross-env.
+  // app.isPackaged is set by electron-builder for installer builds.
+  const devServerUrl = process.env.VITE_DEV_SERVER_URL;
+  if (!app.isPackaged && devServerUrl) {
+    console.log('[WINDOW] Dev mode — loading', devServerUrl);
+    win.loadURL(devServerUrl);
+  } else {
+    const prodPath = path.join(__dirname, '../../dist/renderer/index.html');
+    console.log('[WINDOW] Production mode — loading', prodPath);
+    win.loadFile(prodPath);
+  }
 
   // Show window only after content is ready — avoids blank flash
   win.once('ready-to-show', () => {

src/renderer/components/layout/AppShell.tsx

@@ -27,7 +27,7 @@ export function AppShell() {
       <main className="h-screen w-screen overflow-hidden bg-background">
         <ResizablePanelGroup
           direction="horizontal"
-          onLayout={(sizes) => setPaneSizes({ sidebar: 0, editor: sizes[0], preview: sizes[1] })}
+          onLayoutChange={(sizes) => setPaneSizes({ sidebar: 0, editor: sizes[0], preview: sizes[1] })}
         >
           <ResizablePanel defaultSize={previewVisible ? 50 : 100} minSize={20}>
             <section className="h-full bg-background">
@@ -58,7 +58,7 @@ export function AppShell() {
       <main className="flex-1 overflow-hidden">
         <ResizablePanelGroup
           direction="horizontal"
-          onLayout={(sizes) => setPaneSizes({ sidebar: sizes[0], editor: sizes[1], preview: sizes[2] })}
+          onLayoutChange={(sizes) => setPaneSizes({ sidebar: sizes[0], editor: sizes[1], preview: sizes[2] })}
         >
           {sidebarVisible && (
             <>

src/renderer/index.html

@@ -2,7 +2,7 @@
 <html lang="en">
 <head>
   <meta charset="UTF-8">
-  <meta http-equiv="Content-Security-Policy" content="default-src 'self'; script-src 'self' 'unsafe-inline' 'unsafe-eval'; style-src 'self' 'unsafe-inline'; img-src 'self' data: blob:; font-src 'self' data:; connect-src 'self';">
+  <meta http-equiv="Content-Security-Policy" content="default-src 'self'; script-src 'self' 'unsafe-inline' 'unsafe-eval'; style-src 'self' 'unsafe-inline' https://fonts.googleapis.com; img-src 'self' data: blob:; font-src 'self' data: https://fonts.gstatic.com; connect-src 'self' https://fonts.googleapis.com https://fonts.gstatic.com;">
   <meta name="viewport" content="width=device-width, initial-scale=1.0">
   <title>MarkdownConverter</title>
   <link rel="preconnect" href="https://fonts.googleapis.com">

tests/component/layout/AppShell.test.tsx

@@ -6,7 +6,7 @@ import { useAppStore } from '@/stores/app-store';
 
 // Mock react-resizable-panels for jsdom environment
 vi.mock('@/components/ui/resizable', () => ({
-  ResizablePanelGroup: ({ children, direction, onLayout }: any) => (
+  ResizablePanelGroup: ({ children, direction, onLayoutChange }: any) => (
     <div data-testid="resizable-panel-group" data-direction={direction}>
       {children}
     </div>