Detect subagent tool_call events (Agent/Task/dispatch_agent), auto-spawn
child agent panes with parent/child navigation. Messages with parentId
are routed to child panes; parent session keeps its own messages.
- agents.svelte.ts: parent/child hierarchy fields, findChildByToolUseId,
getChildSessions, parent-aware createAgentSession/removeAgentSession
- agent-dispatcher.ts: SUBAGENT_TOOL_NAMES detection, toolUseToChildPane
routing map, spawnSubagentPane with auto-grouping under parent title
- AgentPane.svelte: parent link bar (SUB badge), children bar (chips
with status colors), clickable navigation between parent/child
- SessionList.svelte: subagent panes show arrow icon instead of asterisk
Agent tree visualization (SVG) with horizontal layout and bezier edges.
Global status bar with pane counts, active agents pulse, token/cost totals.
Toast notification system with auto-dismiss and agent dispatcher integration.
Settings dialog with SQLite persistence for shell, cwd, and max panes.
Keyboard shortcuts: Ctrl+W close pane, Ctrl+, open settings.
Phase 3 polish: dispatcher listens for sidecar-exited events and marks
running sessions as error. AgentPane shows "Restart Sidecar" button on
error. Auto-scroll disables when user scrolls >50px from bottom with
"Scroll to bottom" button. Added agent_restart Tauri command.
Svelte 5 $state/$derived runes only work in .svelte and .svelte.ts
files. The stores had plain .ts extensions, causing a blank screen with
"rune_outside_svelte" runtime error. Renamed all three store files and
updated import paths across 5 consuming files.
