feat(gui): goal wire domain, client goal state, and docked goal bar

- apiproxy goals RPC domain (get/create/edit/pause/resume/complete/clear)
  with CAS refs, zod schemas, and fetch client/handler wiring
- client runtime session goal state: live goal/change meta triggers a
  coalesced refetch; mutations fold transport errors into RpcResult
- web GoalBar: docked strip above the composer (sparkle, phase label,
  truncated objective, inline edit, clear; resume when paused); creation
  stays on the /goal command
- GoalBarActions in the ui-conversation contract layer; IconSparkle16
  moves to ui-primitives icons

packages/client/ui-conversation/tests/chat-stats-bash-sample.spec.tsx

@@ -31,6 +31,7 @@ function snapshotBase(): ConversationSnapshot {
     sessionId: SID, nodes: [], foldDegraded: false, partial: null, runningCalls: [],
     pending: [], running: false, removed: false, openState: 'open', openError: null,
     hasMore: false, loadingOlder: false, promptError: null, lastAgentError: null,
+    goal: undefined,
   }
 }