v0.8.0

Added

• Cross-process write lease for sessions — a session/prompt turn now takes an advisory per-conversation lockfile for its duration (acquired only after the existing in-process prompt_lock, so an overlapping turn on the same process can't take and then drop the lockfile out from under the one that's actually running), so the desktop app's embedded core and a separately-spawned CLI sharing ~/.openheim/history/ can no longer both write the same conversation at once. A second process's overlapping turn fails fast with Error::SessionLocked instead of racing; a crashed holder's lease is detected and taken over automatically. save_conversation also now refuses a stale rewrite when the on-disk history has diverged from what the caller loaded.
• OpenAI-compatible reasoning models (GLM, DeepSeek, …) now persist and replay their extended-thinking output instead of losing it once streamed to the UI — thinking survives session reload. It's never replayed back to the provider on continuation requests, to keep growing reasoning traces from bloating context.

Fixed

• A prompt in flight on one connection no longer lets a second connection load a stale, un-updating history snapshot. session/load's history replay is a one-shot dump of what's on disk; a turn still streaming only pushes updates to the connection that called session/prompt. A second connection loading the same session mid-turn previously got back a snapshot that would never catch up. session/load now rejects outright while a prompt is in flight for that session, instead of silently handing back a picture that's already stale.
• session/load's response now reports the session's actual mode instead of always claiming the default. The mode advertised in LoadSessionResponse was hardcoded to AgentMode::Code regardless of what session/set_mode had actually set for a live session, so a client reattaching to an existing session saw the wrong mode in its UI until the next explicit mode change.
• Reattaching to a session via session/load no longer drops images from replayed user messages. History replay reconstructed a user turn from msg.text(), which only concatenates Text blocks — an image attached to the original prompt was silently missing from the replayed conversation. Every persisted block is now iterated in order, so Image blocks (alongside Text) are restored the same way they'd have appeared live.

Changed

• Project logo — swapped the SVG hexagon mark in the README for the new openheim-logo.png.