fix(deps): migrate validate-color to official npm package

[lewinpauli]

couldnt start on fedora 43 gnome 49 branch master

The Bug

yarn install was not possible and created the following error:

yarn install
yarn install v1.22.22
[1/5] Validating package.json...
[2/5] Resolving packages...
[3/5] Fetching packages...
info There appears to be trouble with your network connection. Retrying...
error Error: https://gitpkg.now.sh/dreamyguy/validate-color/src/validate-color: Request failed "402 Payment Required"
at Request.<anonymous> (/usr/lib/node_modules_22/yarn/lib/util/request-manager.js:521:16)
at Request.emit (node:events:519:28)
at Request.onRequestResponse (/usr/lib/node_modules_22/yarn/node_modules/request/request.js:1059:10)
at ClientRequest.emit (node:events:519:28)
at HTTPParser.parserOnIncomingClient (node:_http_client:716:27)
at HTTPParser.parserOnHeadersComplete (node:_http_common:121:17)
at TLSSocket.socketOnData (node:_http_client:558:22)
at TLSSocket.emit (node:events:519:28)
at addChunk (node:internal/streams/readable:561:12)
at readableAddChunkPushByteMode (node:internal/streams/readable:512:3)
info Visit https://yarnpkg.com/en/docs/cli/install for documentation about this command.
info There appears to be trouble with your network connection. Retrying...
info There appears to be trouble with your network connection. Retrying...
info There appears to be trouble with your network connection. Retrying.

after yarn install was fixed, Gnome Extension manager showed the following errors:

SyntaxError: The requested module 'file:///home/coco/.local/share/gnome-shell/extensions/pano@elhan.io/thirdparty/validate_color.js' doesn't provide an export named: 'validateHTMLColorHex' @ file:///home/coco/.local/share/gnome-shell/extensions/pano@elhan.io/extension.js:59:10

The Fix

Migrate validate-color to official npm package

Problem
The validate-color dependency was using a custom GitHub package URL (https://gitpkg.now.sh/dreamyguy/validate-color/src/validate-color) which caused build issues with named exports not being properly re-exported during the rollup bundling process.

Changes Made

1. package.json
   Updated validate-color dependency from gitpkg URL to official npm registry version ^2.2.4
2. rollup.config.mjs
   Added namedExportsConfig object to explicitly define named exports for packages that need them:
   validateHTMLColorName
   validateHTMLColorSpecialName
   validateHTMLColorHex
   validateHTMLColorRgb
   validateHTMLColorHsl
   validateHTMLColorHwb
   validateHTMLColorLab
   validateHTMLColorLch
   validateHTMLColor
   Enhanced commonjs() plugin configuration with requireReturnsDefault: 'auto' and conditional defaultIsModuleExports
   Added custom rollup plugin (export-named) to properly re-export named exports from bundled packages
3. Added Gnome session restart to readme (including screenshot)

yarn install && yarn build && pano works now

Fixes
#378
#281

Type of change

Please delete options that are not relevant.

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to not work as expected)
• This change requires a documentation update

Checklist

• My code follows the style guidelines of this project
• My commits follow the commit standards of this project
• I have performed a self-review of my own code
• I have commented my code, particularly in hard-to-understand areas
• I have made corresponding changes to the documentation
• My changes generate no new warnings
• I have checked my code and corrected any misspellings

[wanstu]

Ubuntu 25.10 x86_64 Gnome shell 49.0
I successfully built and installed using this pull request. Thank you!