cursor token_details read into Usage

What it does

Decodes the cursor wire's checkpoint message, reads the token details it carries, and feeds them into Usage, so the context meter and auto-compaction see a number on this wire.

Source

ganja-code-shlm (cursor's token_details read into Usage).

The bead is closed when this issue is published, with its external reference pointing here (#38).

File and line references in this issue are to main as of 75a7a92.

Against the three criteria

• Direction (README): The README says nothing about showing usage (README.md:28-29).
• Today's terminal users: The cursor wire emits no Usage, so the context meter stays still and auto-compaction never fires; /compact is the only door, and since D553 the request grows with the transcript.
• Evidence: The checkpoint field is logged by number and size only (crates/ganja-provider/src/provider/cursor/decode.rs:373-381, crates/ganja-provider/src/provider/cursor/decode.rs:552). The first step is to decode it and log what it holds on a live turn, which needs a stored sign-in.

Depends on

Nothing. It could share the occasion of #91's live probe.

Verdict

• Verdict: park
• Reopens: at the next landing that touches the cursor wire — possibly the same occasion as the live probe #91 needs.
• Exception to the probe rule: no.
• Date: 2026-09-19
• Verdict ticket: #45

Theme: #58

Start in crates/ganja-provider/src/provider/cursor/decode.rs at lines 373-381 and 552, then run a live cursor turn using the stored sign-in to inspect the checkpoint field's contents. Confirm how its token_details can be decoded into Usage so the context meter and auto-compaction receive a value; the issue is done when that wire reports usable usage.