Reimplement password strength as ViewComponent, custom element

[aduth]

🛠 Summary of changes

Refactors password strength UI element as a combination ViewComponent component + JavaScript custom element.

As part of this work, removes ad-hoc text size reduction previously applied to strength and feedback elements.

The refactoring adopts frontend architecture conventions, namely:

• TypeScript instead of (non-typechecked) JavaScript
• Custom elements instead of one-off packs
• ViewComponent component instead of Rails view partial
• BEM CSS class naming without abbreviations instead of nonstandard class names (see related comment)
• Component-specific stylesheets instead of main stylesheet include
• Dependencies defined within workspace packages

Related: #9811

Why?

• Simplify usage and ensures consistency by embedding password strength as a subcomponent of the existing password confirmation experience, to
• Improves maintainability by making it easier to test the custom element, which has more controllable side-effects than a JavaScript pack
• Reduces size of main application stylesheet to improve load times in critical paths
• Aligns text styling to current Figma designs
• Improves accessibility and usability by increasing the font size of text feedback

📜 Testing Plan

Verify there are no regressions in the behavior of password strength:

1. Go to http://localhost:3000
2. Sign in
3. On account dashboard, click Edit Password
4. (Reauthenticate if prompted)
5. Enter a new password
6. Observe password feedback

👀 Screenshots

Before	After

[aduth]

Okay, this should be essentially complete now. At this point, I might just wait for the content freeze to lapse to merge, despite not really making any meaningful content changes.