fix: release TypeType 1.5.1

[Priveetee]

Summary

• release TypeType 1.5.1 across Frontend, Server, Token and Downloader
• load YouTube captions directly from the viewer browser
• preserve manual, automatically generated and translated caption tracks
• bind anonymous YouTube token generation to the page-native BotGuard context
• align all released service versions on 1.5.1
• publish the 1.5.1 release notes

Production behavior

• YouTube timed-text requests no longer use shared Server egress addresses
• subtitle-only upstream 429 responses no longer prevent web captions
• NicoNico and BiliBili subtitle handling remains unchanged
• anonymous YouTube sessions use a matching page context, event identifier and visitor session

Deployment requirements

No configuration or database migration is required.

Deploy the four 1.5.1 stable images after their component workflows publish the exact version tags.

Tests

Frontend, Server, Token and Downloader passed their complete local validation suites and component CI gates. Central stack CI is the final release gate.

Rollback

• restore Frontend ghcr.io/typetype-video/typetype@sha256:025ecbe560e89ea9d17c7422a305c66e37e90e17882c4807c5b5c3286a0a412f
• restore Server ghcr.io/typetype-video/typetype-server@sha256:0fc635263e8ff5048fead1ef6f094e63c0beb0a1f5c9e56b7820a53be4ddd762
• restore Token ghcr.io/typetype-video/typetype-token@sha256:2912d64564e5e4f3058216cc2835aa87e18482659cedc09e0ce9dfc8b16e6fe9
• restore Downloader ghcr.io/typetype-video/typetype-downloader@sha256:c3f0cfd83898513a478c50ccfd64daef39f1902322844097f3daab3ffb65e9da