Add Authier password manager

[capaj]

Summary

• Add Authier to the Password Managers table.
• Describe its current public scope: credentials and TOTP codes, browser extensions, a web vault, client-side encrypted sync, and trusted-device approval.
• Keep the early-stage and no-independent-audit limitations explicit in the catalogue row.

Verification

• git diff --check
• Confirmed the change is exactly one README row in the existing three-column table.
• Confirmed the canonical homepage, https://www.authier.pm/, returns HTTP 200.
• Confirmed the repository license is GNU AGPL v3; the project applies the license as AGPL-3.0-or-later.

This repository has no automated test or build configuration, so validation is limited to the Markdown diff, table shape, factual source review, and live target link.

Disclosure

I maintain Authier and am proposing my own project for inclusion. OpenAI Codex helped research the catalogue fit, verify the public claims and deployment behavior, and prepare this one-line contribution and pull-request text. I reviewed the change and take responsibility for its contents.

Authier is early-stage and has not undergone an independent security audit.