Collapse sequential Read tool uses into a "Read N files" card

[mcintyre94]

Summary

• When Claude reads multiple files back-to-back, the individual tool cards are now grouped into a single compact "Read N files" row — reducing chat noise for read-heavy sessions
• Tapping the row opens a sheet listing each file in a DisclosureGroup, with the file content expandable inline
• The card updates live during streaming: when a second Read arrives, the first single-file card is upgraded to the group in place
• Single reads continue to behave exactly as before

Implementation notes

• New ReadGroupCard model (@Observable) holds an array of ToolUseCards and exposes allComplete / elapsedString
• ChatContent gains a .readGroup(ReadGroupCard) case; PersistedChatContent gains a matching .readGroup([PersistedToolUse]) case for round-trip persistence
• A single static func groupReadCard(_:into:) helper owns the grouping logic (searches backwards past interleaved .toolResult items); used by live streaming, replay buffer, and parseSessionJSONL
• activeToolLabel, rebuildToolUseIndex, and result-linking all updated to look inside readGroup cards

Test plan

• Chat where Claude reads a single file — card renders as before (ToolStepRow, taps to ToolDetailSheet)
• Chat where Claude reads 2+ files sequentially — cards collapse to "Read N files" row with correct elapsed time
• Tap "Read N files" row — sheet opens showing all files; each expands to show content
• During streaming: first read shows normally; second read causes live upgrade to group card; shimmer still shows for the active read
• Interrupt mid-read-group — muted strikethrough row shown
• Persist and reload — group survives round-trip (reloaded as ReadGroupCard via .readGroup persistence case)
• Session JSONL load (resume from remote session) — reads grouped correctly via parseSessionJSONL

🤖 Generated with Claude Code