Let me scroll through an old session before committing to resume it

Problem

When opening an old session, the chooser forces a commit upfront:

This session is 2d 19h old and 169.2k tokens.

Resuming the full session will consume a substantial portion of your usage limits.
We recommend resuming from a summary.

  ❯ 1. Resume from summary (recommended)
    2. Resume full session as-is
    3. Don't ask me again

Both options load the session into context (full or summarized) before I've even seen what's in it. I just want to open it and scroll — read the transcript, remember what was going on, look at the last few turns — and only then decide whether to resume full, compact/summarize, or close it and walk away.

Proposed behavior

Opening an old session should drop me into a read-only view of the transcript with no context-window cost. The "how do you want to resume?" decision happens at the moment I try to send a new message, not at the moment I open the session.

Flow:

1. Pick session from agents view → transcript opens, scrollable, no tokens spent.
2. I scroll, read, decide.
3. First time I type a message and hit send → that's when the chooser appears: resume full, resume from summary, cancel.

This separates "view" from "activate." Today they're fused.

Why it matters

The current UX punishes curiosity. If I have several old sessions and want to pick the right one, or just remind myself what I was doing, I have to either pay the token cost or use out-of-band tools (grep the JSONL). Most users won't know the out-of-band path exists.