Storage Asset Management & API Key UI Overhaul

This release gives every user visibility and control over their stored files, and rebuilds the API key management experience.

Storage Asset Management Page

• A new Settings > Storage page lets users manage their files in S3-compatible storage: list uploads with usage stats, preview assets, generate presigned download links, and delete files individually or in bulk.
• It is backed by new authenticated /assets Hono routes — every operation is strictly scoped to the user's own storage prefix, with thorough key validation and 300+ lines of service tests.

API Keys & Login Experience

• The API key settings were rebuilt around a table with a per-key actions menu (details, test, delete) and an on-demand verification dialog, so users can confirm a freshly created key actually works without leaving the page.
• The OTP login form layout was polished, with cleaner alignment of the password field and the forgot-password link.