fix: Generate valid manifest for Firefox MV3

[aklinker1]

This closes #226

• Manifest background changes
• WXT dev mode permissions are correct with no warnings Disable dev mode for Firefox MV3
  
  Dev mode is broken, see: Default Firefox to MV3 #230 and https://bugzilla.mozilla.org/show_bug.cgi?id=1864284
• Support page_action and action at the same time

  "Firefox retains the page action API, key, and special shortcut in the developer preview but will merge the page action features into action in a later release."
  https://extensionworkshop.com/documentation/develop/manifest-v3-migration-guide/#browser-action

• CSPs are generated correctly

[netlify]

✅ Deploy Preview for creative-fairy-df92c4 ready!

Name	Link
🔨 Latest commit	ad7c465
🔍 Latest deploy log	https://app.netlify.com/sites/creative-fairy-df92c4/deploys/654fc4e14402720008c23445
😎 Deploy Preview	https://deploy-preview-229--creative-fairy-df92c4.netlify.app
📱 Preview on mobile	Toggle QR Code... Use your smartphone camera to open QR code link.

---

To edit notification comments on pull requests, go to your Netlify site configuration.

[codecov]

Codecov Report

Merging #229 (ad7c465) into main (67ffa44) will decrease coverage by 0.07%.
The diff coverage is 8.33%.

@@            Coverage Diff             @@
##             main     #229      +/-   ##
==========================================
- Coverage   63.85%   63.78%   -0.07%     
==========================================
  Files          74       74              
  Lines        5812     5823      +11     
  Branches      463      466       +3     
==========================================
+ Hits         3711     3714       +3     
- Misses       2064     2072       +8     
  Partials       37       37              

Files	Coverage Δ
src/core/utils/manifest.ts	33.27% <16.66%> (+0.25%)	⬆️
src/core/runners/web-ext.ts	14.66% <0.00%> (-1.28%)	⬇️

📣 Codecov offers a browser extension for seamless coverage viewing on GitHub. Try it in Chrome or Firefox today!