pi v0.84.4: Terminal capability overrides, RPC clear_queue, smarter compaction timing

v0.84.4 opens with terminal capability overrides: environment variables and advanced settings can now override pi’s auto-detected hyperlink, image, and truecolor support. If your terminal emulator lies about what it can render — or a multiplexer strips a capability — the detection result no longer has to be lived with.

Integrations that host pi get two new events: ui_prompt_start and ui_prompt_end distinguish active agent work from time spent waiting on a ctx.ui prompt, which matters for status displays and time-based automation. On the RPC side, clear_queue retrieves and removes queued steering and follow-up messages, and library consumers gain a public detectSupportedImageMimeTypeFromFile() export.

Fullscreen mode gets finer copy semantics: the new fullscreenCopyOnSelect setting disables automatic selection copying, and when it is off, Ctrl+X copies the active selection before falling back to the last assistant message — /tree still copies the selected message either way. Model coverage also grows, with an experimental vision-capable deepseek-v4-flash-vision-exp model reachable through the built-in DeepSeek provider.

The fixes are the quiet highlight. Large tool results that crossed the auto-compaction threshold were previously sent to the provider before compaction could run; pi now compacts between tool execution and the next assistant response within the same run. Resumed sessions with a JSONL file missing its trailing newline no longer corrupt the next appended entry, extension messages sent with triggerTurn: false while the agent runs are appended after the turn’s tool results instead of wedging between a tool call and its result, and Windows aborts no longer crash pi when taskkill.exe is absent from PATH. Each of these fixes links to its tracking issue on the GitHub release page.