EPIC: Agent harness & display — structured events, live feed, chat panel upgrades

[kordless]

Why

The Ghost agent runs well but is a black box: tool calls and model turns exist only inside conversation history + free-form tracing spans — nothing queryable, nothing live. And the chat display is missing the basics users expect (context meter, distill-on-long-context, attachments). This epic makes the harness observable and upgrades the display.

Grounding (code-mapped): run loop sidecar/src/ghost/agent.rs:193-846 (tool dispatch at :647, token Stats at :510-515), event enum ghost/types.rs:6-52, chat SSE ghost/api.rs:50-110, chat UI sidecar/static/shell.html served at GET /shell (main.rs:2990, include_str!), audit-log pattern to copy sidecar/src/audit.rs.

Status discovery

#42 / #46 are already architecturally done — the chat IS a sidecar-served UI (/shell) embedded via a web pane (now a native WebContentsView per #128). Remaining scope is browser-session auth (open the same URL in an external browser with a token). They stay open, re-scoped to that.

Phases

• P0 — Agent split/new targets the FOCUSED pane, not the caller's own pane/tab — 'split in your tab' lands elsewhere #119 caller-context targeting (bug): post_split (main.rs:691) / post_new_tab (main.rs:2920) with window/tab/pane omitted must default to the CALLER's pane (CallerIdentity::Pane), not the focused pane. Small, high-value.
• P1 — Structured log events: capture tool calls and model turns as discrete events #71 structured log events: new event layer capturing tool_call {name, input, output_summary, duration_ms} + model_turn {model, prompt_tokens, completion_tokens} from the run loop into an in-memory ring + rolling JSONL (~/.hyperia/logs/events.<date>.jsonl), following audit.rs.
• P1b — SSE log stream: live feed of agent events over Server-Sent Events #73 SSE live stream: GET /api/logs/stream broadcasting new events (same SSE machinery as ghost chat).
• P1c — Log query/export endpoint: GET /api/logs with filter params #72 query endpoint: GET /api/logs?type=&tool=&session=&since_ms= mirroring /api/audit/search.
• P2 — feat(chat): context length meter — show token usage in Ghost chat panel #43 context meter: render the existing GhostEvent::Stats tokens as a header meter ({used}k / {limit}k, green/yellow/red at 50/80%) in shell.html; sidecar exposes the model's context limit.
• P3 — feat(chat): long-context warning with Distill & Continue and Distill & Replace options #44 long-context distill: warn at 75%/90%; Distill & Continue / Distill & Replace via a summarize turn.
• P4 — feat(chat): image paste and file attachment in Ghost chat input #45 + Agent vision: pass screenshots and crawled images into Ghost agent context #41 attachments & vision: image paste/drag/attach in the chat input → vision blocks; tab_snapshot base64 into agent context.
• P5 — Ghost theme tooling + widget GUI upgrade (color themes) #124 theme tooling + widget GUI, feat(settings): settings agent chat panel + sidecar SettingsSession #53 settings agent session (split from ghost), Tool discoverability: open_web_pane mis-names a tab as a 'pane', web-pane-in-tab is hidden in terminal_split, terminal_status gives no action hints #120 tool discoverability, feat: serve Ghost agent chat as a local web endpoint #42/feat(chat): unify Ghost chat as a sidecar-served UI — Electron embeds via webview, browser opens same URL #46 browser-token auth.

Linked issues (kept open, tracked here)

#119, #71, #72, #73, #43, #44, #45, #41, #124, #53, #120, #42, #46

Work lands on canary. Related: #128 (WebContentsView — the chat panel renders through it).