Add dotenv as gem dependency, fix Dashboards#edit 406

Move dotenv from Gemfile dev dependency to gemspec runtime dependency
so host apps get it automatically. Add missing edit.html.erb template
for dashboards which caused a 406 Not Acceptable response.

Refactor dashboard chart search implementation

Fix HTML-escaping JSON embed, for new dashboard forms

Align turbo frames between _new_form and _statement_box

Resolves an issue where broadcasts were not resolving/updating the view.

Fix Pagy FrozenError on fresh install

* Test to verify fix
* Improve install message clarity
* Allow sage-rails to use Pagy v9.4 or v43 (avoid conflicts in base app)

Simplify ask/write tabs, adjust cursor styles

Correctly decode HTML entities in data-initial-content

Use data-initial-content to render statements, avoid direct div rende…

…ring

Injecting statments directly into the editor's div was forcing
characters like double quotations to be forcibly escaped, resulting in
malformed SQL.

Remove reundant html_escape in statement box

Fix tab toggle visibility in /queries/new (css)