Switch to using a Button component instead of ToolbarButton

[dkotter]

What?

Closes #368

Switch to using a Button component instead of a ToolbarButton component when in normal editing mode (non-template mode)

Why?

In normal editing mode, the title input isn't an actual block and thus doesn't support the normal block toolbar. We more or less "fake" that to inject our generate button when Title Generation is turned on. This leads to some weirdness though where the loading state and the active state would both show.

To fix, we now load a normal Button component and only load the ToolbarButton component when in template editing mode (where the title input is a block). Note this does change the design a bit (see screenshots below).

How?

• When in "standalone" mode, use a Button component instead of a ToolbarButton component
• When we inject our component, load it in "standalone" mode

Use of AI Tools

Use Cursor running GPT-5.3 Codex to investigate options beyond just overriding core CSS. Final testing and adjustments done by me

Testing Instructions

1. Checkout this PR and run npm i && npm run build
2. Turn on Title Generation
3. Edit a post and click into the title input
4. Ensure the Re-generate button shows
5. Click it and ensure it works
6. Switch into template editing mode
7. Click into the title input and ensure a new Re-generate button shows
8. Click it and ensure it works

Screenshots

Before	After

[github-actions]

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[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 63.81%. Comparing base (aa6409b) to head (8e456de).
⚠️ Report is 126 commits behind head on develop.

Additional details and impacted files

@@            Coverage Diff             @@
##             develop     #375   +/-   ##
==========================================
  Coverage      63.81%   63.81%           
  Complexity       684      684           
==========================================
  Files             49       49           
  Lines           3529     3529           
==========================================
  Hits            2252     2252           
  Misses          1277     1277           

Flag	Coverage Δ
unit	63.81% <ø> (ø)

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[jeffpaul]

Looks good, but let's hold on merging until we determine whether we need to revert #340 or not ahead of the 0.7.0 release.

[jeffpaul]

@dkotter I think this one's good to merge for 0.7.0?