Agent Hub previously pre-rendered every registry row and resolved each
row's observer via getSessions().find, which copy-sorts the full observer
map. On large rosters that made open/selection/age-tick O(all rows) and
observer lookup near O(N^2 log N).
- Add SessionObserverRegistry.getSession(id) for O(1) Map lookup
- Lazy-render hub rows around the selection within the terminal line budget
- Keep ordering, selection, status counts, overflow, badges, and task lines
- Add 10k-row regression covering bounded getSession/render work
- Merged the executor-reported fallback flag into the live-session badge path so a Fireworks Fast to base degrade (which arms no session retry state) keeps its provenance.
- Added a live-row regression test for a fallback that populates no retryFallbackModel.
Fixes#6316
- Threaded a resolvedModelIsFallback flag through AgentProgress and SingleResult.
- Set the flag from the executor retry-fallback handlers and settled results.
- Rendered the observer/no-session hub path as fallback -> provider/model.
- Added an observer-only fallback-badge regression test.
Fixes#6316
- Redesigned agent hub entries as two-line cards, separating identity and status from task descriptions.
- Added explicit model and thinking level badges to agent status information.
- Updated agent hub rendering to support multi-line entries and adaptive vertical scrolling based on row height.
- Simplified status display by using glyphs instead of redundant status labels.
- Adjusted rendering logic to prioritize displaying agent task summaries on an independent indented line.
- Added throttling and debouncing to HUD data rendering and observer UI synchronization to coalesce update bursts.
- Constrained the subagent HUD display to a maximum of 8 rows with a truncation notice for hidden sessions.
- Enhanced the session observer registry to categorize update types, enabling more granular UI reconciliation.
- Verified render coalescing and display truncation behavior with comprehensive integration tests using fake timers.
- Added no-op setters to process.stdout properties in test geometry stubs.
- Prevented potential errors when code under test attempts to reassign stdout dimensions.
- Sanitized newlines from agent hub display text to ensure single-line output.
- Enforced line clamping during render to prevent terminal wrapping.
- Added test coverage to verify output truncation and newline removal.
- Added a helper that renders hub output and extracts ordered agent IDs.
- Replaced positional string assertions with explicit row-order expectations.
- Awaited asynchronous theme initialization in test setup.
- Captured each row's initial position in AgentHubOverlayComponent on first refresh and reused it on later refreshes.
- Changed subsequent sorting to prioritize status then prior row position, so activity updates no longer reordered visible rows.
- Added a regression test that verifies row ordering stays stable when activity changes and new agents append at the end.
Kyle McCleary