OpenCode 1.4.0 aflaai

Breaking Changes in SDK
Due to some performance issues we had to make a few breaking changes in our data model.

Diff metadata
The diffs contained in the metadata for the edit and patch tool will no longer contain a to and from field with full file contents. they will only contain a patch field with the unified diff
Additionally all snapshot diffs contained in user message and session diff will follow this format

UserMessage.variant
Before the user message had a variant field - it is now nested under model so userMessage.model.variant

Core
- Added OTLP observability export support.
- Fixed failed web fetches leaving stale timeouts behind.
- Improved opencode login transport error messages.
- Retried Alibaba provider rate-limit errors instead of failing immediately.
- Kept model variants scoped to the selected model.
- Added full HTTP proxy support.
- Fixed OpenRouter provider issues.
- Aligned GitHub Copilot Anthropic reasoning levels and removed incorrect Qwen variants.
- Reduced TypeScript LSP memory use by using the native project config. (@derekbar90)

TUI
- Added a keybinding option for "Switch model variant". (@ariane-emory)
- Added PDF drag and drop for attachments. (@gitpush-gitpaid)
- Added opencode run --dangerously-skip-permissions to auto-approve non-denied permission prompts.

Desktop
- Improved subagent sessions with clearer titles, navigation, and progress states.
- Moved auto-accept permissions into Settings.
- Showed full file names on attachment chips.
Thank you to 4 community contributors:
- @derekbar90:
- fix(lsp): MEMORY LEAK: ensure typescript server uses native project config (#19953)
- @mchenco:
- docs: update Cloudflare provider setup to reflect /connect prompt flow (#20589)
- @gitpush-gitpaid:
- feat(opencode): Add PDF attachment Drag and Drop (#16926)
- @ariane-emory:
- fix(tui): use sentence case for theme mode command palette items (#21192)
- feat(tui): allow variant_list keybind for the "Switch model variant" command (#21185)