[trissim]

Change

Required ContextReading presentation, paired with Toad #693. Supersedes the rejected runtime status-label and nullable wire_fields designs.

• ContextReading uses the existing DeclaredFamily/FieldCodec mechanism. ContextUsage owns measured label_parts()/status_text(); UnmeasuredContext owns the unmeasured answer. No nullable context reading or wire_fields method is exposed by this family.
• RuntimeInfo.context_reading() returns the family. CoordinationChangedUpdate carries required model and ContextReading values; status_label derives from those same values, not a separately stored label.
• ThreadConfiguration constructs the update directly. RuntimeInfo.status_label, configuration_update callbacks/partial machinery and the nullable context wire projection are deleted.
• Existing model selection/session/runtime fallback remains in resolve_thread_model. It is NOT accepted as a per-row sidebar path. Canonical saved-selection carry and deletion of that fallback remain separate unfinished work due 17:00 EDT.
• Current main is integrated normally. No data carry, original-session modification, provider input or installation was performed.

Evidence and acceptance

Current owner NRA source enumeration and semantic diff: core-change-report/.artifacts/sidebar-observation/task-b-{before,after}.json/.log and task-b-toad.diff. Zero parse omissions; dynamic resolution remains a stated limitation. The previous owner's ratchet result applies to its preceding checkpoint, not this head.

Final Core head 2fb445b94fc22ed58a365709f4a873ca53e4a303, paired Toad a64bca902416fd7881d9676b79040f134ad513fd. Both existing production debt checks pass without positive deltas, whitespace checks pass, and the exact manifest/lock passes uv's offline check. Focused Core ACP codec checks: 2 passed in 0.15s. The merged TranscriptDraftUpdate constructor census and strict codec validation exception contract were updated in the existing Core test; earlier failed results are retained. No Toad tests were run.

Actual plain-st/Xvfb :229 saved-session application check uses installed runtime 184023Z plus both source overlays: saved history, DM history/activity/prompt/model-only status, channel history without Active, real unsent mention completion and Core-owned initial unmeasured text are visible. No crash file or ACP prompt submission. Fitted-window evidence supersedes the original cropped screenshots and mistaken blank-DM report; details remain in .artifacts/sidebar-observation/task-b-live/.

Shared-installed/native acceptance is NOT claimed: session/load against the older running Core 496609b owner refuses Expected a string family kind. The rollout must align the reviewed native-owner protocol; no legacy decoder, uncertain-input replay, manual restart or publication was performed. Review and Codex paired publication remain required. Toad's four residual ContextUnavailable references are zero in its paired head; Core's ContextReading owns the unmeasured text.