[Feature Request] Add official read-only transcript viewer for session logs

Bug Description
Feature request: official read-only viewer for Claude Code session transcripts

Claude Code stores every session as a .jsonl transcript under ~/.claude/projects/<project>/<session-id>.jsonl. The only built-in way to revisit a past session today is "claude --resume <id>", which reopens it as a live, interactive session. There is no lightweight, read-only way to browse a past session, search across multiple sessions or projects, or read a transcript in a clean, human-friendly format without continuing the conversation.

I would like Claude Code to ship an official, read-only transcript viewer for these local session logs, for example "claude --show <id>" for read-only viewing, or a small bundled web UI. It should let a user open one or more .jsonl session files (ideally a whole project folder at once), browse and search across sessions grouped by project, and read the conversation rendered nicely (markdown, tool calls and results, thinking blocks collapsible) without needing --resume.

To scratch this itch myself, I built a small prototype: a self-contained, single-file local viewer that loads .jsonl files entirely client-side, with nothing uploaded anywhere, and renders them as a readable, searchable transcript grouped by project, with collapsible tool calls, thinking, and local-command noise. Sharing it as a concrete example of what would be useful as an official feature:

https://claude.ai/code/artifact/289806a3-0195-4e71-b7e1-5e88c1ecb200

Environment Info

• Platform: win32
• Terminal: windows-terminal
• Version: 2.1.234
• Feedback ID: 4de80faf-66bc-4d39-b483-74fae324a1bf

Errors

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