[trissim]

Summary

1 commit, 2 files, +4/-4. Channel-change repaint requests go from every member to only the channel's pin delta. The blanket group sync spelling goes 5 -> 4 in sidebar_tree.py.

channel unread changed
repaint every thread
ask every open tab whether it changed
nothing changed

Channel presentation owns the pin delta

Before: ChannelGroup.present painted the header and discarded the difference between its previous and new channel. ChangedChannels.apply_comms then marked every member changed. Every resulting ThreadStatusRow.show calls SessionNavigation.thread_row before its existing equality guard; that method walks all open session entries.

After: ChannelGroup.present(channel) -> frozenset[str] retains all existing header work and returns previous.pinned_members ^ channel.pinned_members. ChangedChannels passes that result directly into group.sync_members(...).

Class structure is unchanged: ChannelGroup(SidebarGroup[ThreadRow]), SidebarGroup(KeyedRows[str], VerticalGroup), and the existing SidebarChange family remain the owners. No cache, throttle, shadow state, wrapper or equality workaround was added. One blanket repaint route (2 statements) is replaced with the existing owner's result (1 statement).

Work removed and preservation scope

Let M be existing attached member rows in one changed group, T open session entries, and D the pin symmetric difference among those rows. With stable membership:

Channel update	Before row-show calls / tab projections	After
Unread/activity/label only; unchanged pins	M / M*T	0 / 0
Pin changes	M / M*T	D / D*T

These are static work counts, not elapsed timings or measured p99.9. Membership reconciliation still traverses model keys; no claim that the entire channel update is constant time.

• KeyedRows.reconcile_keys creates and paints new/transferred or unattached rows independently of the changed set, removes retired keys and reorders from current keys. That algorithm is unchanged.
• RowReconciliation.finish keeps its full-member synchronization for outstanding transfers.
• AllSidebarRows keeps full catch-up for hidden/reopened/rebound views. New groups still paint through on_mount.
• ChangedThreads and app ThreadRowStateChanged still repaint actual thread changes.
• Search filtering/reconciliation and selection/reader handling are untouched.
• Only the per-member pin input comes from the channel; thread content comes from shown.threads.rows and app session state.

Source evidence

Before inventory: NRA parse_python_module_roots + ModuleSyntaxIndex, Toad production source plus Core ui_model, 318 parsed modules, completed RC0. It records class bases, imports, relevant owner bodies and attribute reads/writes; all matching present, sync_members, show_member, reconciliation, pin and thread-row consumers were inspected. This is syntax evidence, not a dynamic binding/MRO proof; unrelated present names remain unmatched rather than being declared sidebar callers. No parse error was printed.

Owner/consumer sites before this patch:

• comms_sidebar.py:100,132,146,270: channel presentation, pin projection, member sync, thread rendering.
• sidebar_tree.py:180,376,434,457,483,722: reconciliation, catch-up, channel changes, thread changes, search.
• session_navigation.py:178: per-row session traversal.
• Core ui_model/sidebar.py:81,189: immutable channel row and separately flushed channel/thread models.

Required check:

git grep -h -c -F 'group.sync_members(frozenset(group.member_keys))' -- src/toad/widgets/sidebar_tree.py
# before: 5; after: 4

No pytest, synthetic app, fixture, full suite or local NRA gate was run. The integration owner still owes installation and the affected real-application journey/total-frame p99.9 measurement; this PR does not claim those results.

Assumed:

• Core channel/thread keyed publications and app thread-row events continue to deliver thread-content/session-state changes, as their existing declarations specify.
• Four retained broad sync sites are intentional catch-up/search/transfer/relationship behavior, not this channel-change defect.
• Open PRs Replace sidebar worker absence with a nominal unscheduled value #1356 and Finish central key declarations across Toad consumers #1338 touch the same files in unrelated worker/navigation declarations; their changes were inspected and not copied or edited here.

[Copilot]

Copilot was unable to review this pull request because the user who requested the review has insufficient remaining quota.

An organization owner can choose the repository organization as the billing source for reviews requested by members with a paid Copilot license. Learn about Copilot code review billing.