`imageLimits` is a boot constant every Session shares: the unit stores no
per-Session state (`stateSchema: z.null()`, `apply: state => state`) and its
view returns `ctx.attachments.imageLimits`. A list row therefore repeated one
host-wide capability fact on every row. It now carries the summary mark like
the three log-derived units, so a summary read skips it while an opened Session
still receives it through `session/follow`, the control baseline, and
`session.projections`.
No other logic changes: the registration, its schema, its constant view, and
the host-side prompt validation keep reading `ctx.attachments` directly.
A Session-list row no longer carries every registered client view: the three
units whose values a list row never renders (`turnOutline`, `sessionStats`,
and `todos`) are excluded, which removes the whole-log turn outline and the
figure and todo payloads from every row. An opened Session is unchanged —
`session/follow`, the `session/control` baseline, and `session.projections`
still serve every projected key.
The exclusion is one type-level mark plus one registration interlock:
`SessionProjectionSummaryExcluded<T>` marks a map entry, and
`ProjectionDefinition.wire` requires `summary: false` exactly on a marked key
and rejects it everywhere else, so the mark and the declaration cannot drift.
A nullable entry keeps `null` outside the wrapper, so `todos` stays
`TodoItem[] | null`. `summaryKeys()` returns the derived set, stable until a
registration or its disposal changes the key table, and the existing
key-taking read faces (`cachedSnapshot`, `viewCheckpoint`) accept that set
directly, so summaries need no separate read face and no per-read key copy.
`packages/api/session-controller/src/list.ts` passes the set to the live and
cold cached faces; `cachedPredecessorTitle` is untouched.
Client types only: `SessionSummary.projectionValues` narrows to
`SessionProjectionSummaryValues`, `SessionProjectionSnapshot.values` keeps
every view value with the mark stripped, and no wire field or client name
changed. The cache, subsystem page, and package README document the summary
rule and the two read faces.