Standardize Embedded Wallets dashboard terminology across docs

## Summary

Standardize references to the Embedded Wallets project dashboard across documentation to use a single canonical term: **Embedded Wallets dashboard**.

## Problem

The docs currently use multiple labels for the same dashboard experience, including:

- "Web3Auth dashboard"
- "Web3Auth Developer Dashboard"
- "Embedded Wallets dashboard"

This inconsistency creates confusion for readers and complicates editorial review.

## Proposed standard

Use **Embedded Wallets dashboard** as the default term in user-facing docs.

## Scope

- Audit all Embedded Wallets docs and quickstarts for dashboard references.
- Replace non-standard variants with **Embedded Wallets dashboard** where context is end-user instructional content.
- Preserve legacy names only when required for historical migration context, with explicit clarification.
- Align CTA/button copy and link text where needed.

## Acceptance criteria

- No remaining user-facing references to "Web3Auth dashboard" in Embedded Wallets docs unless intentionally preserved with rationale.
- A brief style note is added or updated in the relevant docs rules/style guidance for canonical naming.
- Vale/style checks pass after updates.

Start by searching the Embedded Wallets documentation and quickstarts for the listed dashboard variants, then locate the relevant docs style guidance. Replace non-standard user-facing labels, preserve migration references with clarification, update the canonical naming note, and run the Vale/style checks to confirm the acceptance criteria.

Written by the indexing model from the issue text.