Surfaces real subagent-transcript spend grouped by agentType
(workflow-subagent / Explore / general-purpose / …), read from each agent's
sibling .meta.json (cached on CachedFile; session cache bumped 3→4). This makes
ultra/workflow usage visible — the existing Task-input-based "subagents" section
never sees workflow agents. Shown in `report --format json` (claudeAgentTypes)
and a "Claude Agent Types" dashboard panel that renders only when Claude agent
transcripts exist, so it never appears for the other providers.
collectJsonlFiles only read agent transcripts directly under `subagents/`, but
the workflow feature nests them at `subagents/workflows/<wf>/agent-*.jsonl`, so
their tokens were dropped — undercounting whenever workflow/ultracode was on.
Walk the `subagents/` subtree recursively. Verified on real data: a workflow-
using project recovered ~16% of its cost, with no change to other projects.
