v0.8.5 — Multi-Language Support & Pi SDK Upgrade

Features

Multi-language support (i18n) — The entire UI is now localized. Ships with English, Spanish (es), Simplified Chinese (zh-Hans), and Japanese (ja) — over 1,050 translated strings covering every page, menu, toast, tooltip, and dialog. Switch languages in Settings > Appearance. Session titles and AI responses also follow the selected language.
Pi SDK upgrade (0.56.2 → 0.66.1) — Major upgrade spanning multiple upstream releases. Models like GLM 5, GLM 5.1, and Minimax 2.7 should now work thanks to upstream fixes. Also picks up: Bedrock throttling no longer misidentified as context overflow, Anthropic HTTP 413 detection for compaction/retry, Z.ai tool streaming support, OpenAI streaming fixes, and bash output truncation fix. (Fixes #503, addresses #513)

Canonical locale registry — Adding a new language is now a single-file change. The registry auto-derives all language codes, display names, i18n resources, and date-fns locales.
Unified language setting — Removed the duplicate free-text "Language" field from Preferences. The Appearance language dropdown is now the single source of truth for both UI language and AI response language.
i18n developer tooling — Pre-commit hook catches hardcoded English strings in staged .tsx files. Locale parity test ensures all translations stay in sync. localize-agents skill automates adding new languages.

Headless server responses are in English — When using the WebUI connected to a remote headless server, the UI is fully localized (based on browser language), but the AI agent still responds in English. Session titles are also generated in English. Per-client language support for the headless server will be added in a future release.

The free-text "Language" field in Preferences has been removed. Use the language dropdown in Settings > Appearance instead. Existing preferences.json files with a language field are safely ignored.