Revise mobile nav to Bootstrap structure, aligned with Docsy

[ritorhymes]

Summary

To better align with the Docsy migration #41171, which integrates Bootstrap, this PR reworks the mobile header/navigation to use Bootstrap collapse-driven structure and behavior in a Docsy-aligned implementation. The resulting UI is near-identical to the original in form and function with several bug fixes implemented, no impact on desktop, and better maintainability than the prior custom coded solution. A migration plan to Docsy 0.7 with Bootstrap 5.2 is included.

Changes

• Replaces the legacy pushmenu flow with a right-side mobile drawer pattern built on Bootstrap primitives and existing site navigation data.

• Updates versions/languages mobile accordion behavior so both sections are no longer stuck in an always-open state. The versions section is closed by default since it is not universally essential to see immediately. Languages stays open by default to let users quickly navigate to their needed language.

• Localizes mobile navigation ARIA labels for toggle/close controls to improve accessibility and translation support.

Migration Plan for Docsy 0.7 with Bootstrap 5.2

Required for BS5.2 compatibility

1. Update Bootstrap data attributes in layouts/partials/navbar.html

• data-toggle -> data-bs-toggle
• data-target -> data-bs-target
• data-parent -> data-bs-parent

2. Update Bootstrap utility classes in layouts/partials/navbar.html

• ml-* -> ms-*
• mr-* -> me-*
• sr-only -> visually-hidden

Out of scope (optional follow-up)

A) Migrate Bootstrap collapse API calls to native BS5 instances

• $().collapse('hide'|'toggle') -> bootstrap.Collapse instance methods.
• Not required: BS5.2 exposes a jQuery bridge when jQuery is present on window (Docsy 0.7 still loads jQuery). Works as-is unless jQuery is removed or disabled via data-bs-no-jquery.
• Recommended as best practice to remove conditional dependency.

B) Full jQuery-to-vanilla DOM rewrite in nav.js and legacy-script.js

• This is a broader dependency cleanup and not required for BS5.2 navbar compatibility once Bootstrap plugin calls are migrated.

C) Convert current collapse-based drawer to BS5 offcanvas

• Recommended later to reduce custom drawer state/animation code.

Why jQuery calls can survive this migration

• BS5.2 can expose a jQuery bridge when jQuery is present on window and not disabled via data-bs-no-jquery on .
• Result: $().collapse() calls can continue to work under BS5.2 as long as jQuery remains loaded and the bridge is not disabled.
• Because this is conditional behavior, native bootstrap.Collapse calls are still the more durable long-term target.

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[lmktfy]

A nit: this is not a refactor in the way people usually use the word.

[ritorhymes]

What would you recommend as the best way to categorize / describe it?

[lmktfy]

/retitle Revise mobile nav to Bootstrap structure, aligned with Docsy

[lmktfy]

"Revise" not "refactor".

[ritorhymes]

That’s fair.

I was on the fence about using refactor versus migrate, but I used refactor because the intent was to keep the core UX behaviors functionally near-identical while aligning the implementation with the already established dependencies. Reworked is also good too.

[lmktfy]

If this gets an LGTM I am happy to be the approver for it.

[lmktfy]

Might help with #54801