transcript: badge attachments with their type

[Mark-Life]

Problem:

Every attachment row in a session transcript badges as attachment, so a skill listing and a file opened in the IDE look identical until you expand them. Both the inspector row (session-history.tsx) and the CLI row (sessions-history.tsx) label the badge e.toolName ?? e.kind, and attachments have no toolName. The transcript already knows the difference: handleAttachment in packages/core/src/services/sessions/parse.ts stores the raw attachment.type on the event as attachmentType, and nothing rendered it.

Solution:

eventBadgeLabel in packages/core/src/services/sessions/labels.ts is the one badge rule for both transcripts: tool name when there is one, else attachmentType with underscores replaced by spaces, else the bare kind. skill_listing becomes skill listing, opened_file_in_ide becomes opened file in ide. The transform is mechanical rather than a lookup table, so a type Claude starts writing tomorrow reads as words on the day it appears. A missing, empty, or whitespace-only type falls back to attachment.

attachmentType joins ROW_FIELDS in apps/inspector/src/lib/transcript-row.ts, so the memo comparison sees a badge that changed.

Badge width in the CLI: unchanged. BADGE_MAX there is 20, not 12, so opened file in ide (18 chars) renders whole — the render test asserts the full string in an 80-cell frame. A future type longer than 20 chars clips, as tool names already do.

The kind filter's Attachments option is untouched and still selects kind === "attachment", which is not broken but is now coarser than the rows beside it. One gap worth a follow-up: history search matches title, which holds the raw skill_listing, so searching the humanised skill listing finds nothing.

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Security Impact:

None.

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Testing:

packages/core:    5 pass, 0 fail   (test/sessions/labels.test.ts)
apps/inspector:   6 pass, 0 fail
apps/cli:         3 pass, 0 fail   (test/sessions-ui.test.tsx)

The core tests cover skill_listing, opened_file_in_ide, an invented type, and the missing/empty/whitespace fallbacks. The CLI test renders a session of three attachments and asserts the humanised badges appear in the frame. bun run typecheck passes across all 9 packages. Two pre-existing failures in packages/core/test/agents.test.ts are unrelated and fail identically on the base commit. Before, all three rows read attachment; after, only the typeless one does.