Verify each finding against current code. Fix only still-valid issues, skip the
rest with a brief reason, keep changes minimal, and validate.

Inline comments:
In `@frontend/src/components/dashboard/TopContentList.tsx`:
- Around line 25-27: Replace the interactive <div> wrapper in the TopContentList
component with a semantic <button type="button"> to restore keyboard focus and
assistive tech support: change the element that currently uses
onClick={handleClick} and the className "flex items-center gap-3 p-3 rounded-lg
border border-border bg-card hover:shadow-md transition-shadow cursor-pointer"
to a <button type="button"> keeping the same className and onClick handler
(ensure it is not nested inside another button), and remove any non-button-only
attributes if present so the element behaves like a proper button for keyboard
users.

In `@frontend/src/pages/class-detail/ClassNotFoundCard.tsx`:
- Line 9: The flex container in ClassNotFoundCard (the div with className
"bg-[`#E2E7EA`] flex items-center justify-center") lacks a defined height so
items-center has no effect; update that container to include an appropriate
height utility (e.g., h-full, min-h-screen, or a fixed height like
h-96/min-h-[200px] depending on the layout) so the content will actually be
vertically centered.

In `@frontend/src/pages/class-detail/LoadingSkeleton.tsx`:
- Around line 11-21: The skeleton grids use fixed column counts causing overflow
on small screens; update the container div classNames in LoadingSkeleton.tsx to
use responsive Tailwind grid classes (e.g., replace "grid grid-cols-5 gap-4"
with something like "grid grid-cols-1 sm:grid-cols-2 md:grid-cols-3
lg:grid-cols-5 gap-4" for the five-item row, and replace "grid grid-cols-3 gap-6
mb-6" with "grid grid-cols-1 sm:grid-cols-2 md:grid-cols-3 gap-6 mb-6" for the
three-item row) so the Skeleton components resize and wrap appropriately.

In `@frontend/src/pages/class-detail/session-utils.ts`:
- Around line 517-533: The current lookup uses findActiveOverride(classEvents,
session.instance.date) which matches by date only and can pick the wrong
override for sessions on the same day; update the call and matching logic to
consider the session start time as well: parse the session.instance.class_time
start (parts[0]) into a normalized time string or minutes and pass it into
findActiveOverride (e.g., findActiveOverride(classEvents, session.instance.date,
startTime)), then change findActiveOverride to require both date and start-time
equality when selecting an active override so room_id/instructor_id/override_id
resolution uses date+start-time instead of date-only.

In `@frontend/src/pages/class-detail/SessionRow.tsx`:
- Around line 107-110: The clickable row in SessionRow.tsx currently only uses
onClick and cursor-pointer, making it inaccessible to keyboard users; update the
outer div (the element with onClick and className that includes
getBorderClass()) to be focusable and announced as a button by adding
role="button" and tabIndex={0}, and add an onKeyDown handler that invokes the
same onClick callback when Enter or Space is pressed (ensure it prevents default
for Space so the page doesn't scroll). If the row can be disabled, mirror that
state with aria-disabled accordingly.

In `@frontend/src/pages/class-detail/useSessionFilters.ts`:
- Around line 80-84: The block handling statusFilter === 'upcoming' performs an
unnecessary reversal (result = [...result].reverse()) that is later undone by
the chronological sort in the upcomingSessions memo; remove that reverse line so
the filtered array remains in its natural order (keep the filter using
isUpcoming, isCancelled, and isRescheduledFrom) and ensure any length checks
that use filtered continue to work unchanged.

In `@frontend/src/pages/student/ResidentHome.tsx`:
- Around line 101-104: Replace the non-semantic, non-keyboard-operable div
wrapper with a semantic <button type="button"> that preserves the existing
onClick={handleClick} and className (so existing styles and handlers on the
element remain intact); ensure you remove any redundant role or tabIndex
previously added to the div, confirm there are no nested interactive controls
inside the button (or move them out) and if needed add an aria-label prop for
accessibility—locate the wrapper around the favorite item (the element using
handleClick in ResidentHome.tsx / FavoriteItem) and perform this replacement.

---

Outside diff comments:
In `@frontend/src/pages/class-detail/index.tsx`:
- Around line 88-97: The SWR response type re-declares the blockers shape
instead of reusing the existing DeleteBlockers type; update the generic passed
to useSWR in the delete-check hook so ServerResponseOne references
DeleteBlockers (e.g., useSWR<ServerResponseOne<DeleteBlockers>> or
ServerResponseOne<{ can_delete: boolean; blockers: DeleteBlockers }>) so the
deleteCheckResp / mutateDeleteCheck types derive from the single DeleteBlockers
definition used elsewhere.

In `@frontend/src/pages/knowledge-center/VideoViewer.tsx`:
- Around line 28-35: The API.get call in the VideoViewer component can throw and
leave isLoading true; wrap the call to API.get<Video>(`videos/${videoId}`)
inside a try/catch/finally block (within the async effect or handler where this
code lives) so that on success you call setVideo(resp.data) and on failure you
call setError(err?.message || resp?.message) in the catch, and always call
setIsLoading(false) in the finally; reference the VideoViewer component and the
state setters setIsLoading, setVideo, setError and the API.get invocation when
making the change.

Verify each finding against current code. Fix only still-valid issues, skip the
rest with a brief reason, keep changes minimal, and validate.

Inline comments:
In `@frontend/src/layouts/AuthenticatedLayout.tsx`:
- Line 106: Remove the now-unused local variable isResidentKnowledgeCenter from
AuthenticatedLayout (the dead declaration added earlier) to fix the TS6133
error; locate the declaration in AuthenticatedLayout.tsx (near where
contentClass is defined) and delete it, and then run a quick search for any
remaining references to isResidentKnowledgeCenter to ensure nothing else depends
on it before committing.

In `@frontend/src/lib/formatters.ts`:
- Around line 242-247: In formatDurationStr, guard against malformed time inputs
by validating the numeric results from timeToMinutes before computing duration:
call timeToMinutes(startTime) and timeToMinutes(endTime), ensure both are finite
numbers (e.g., using Number.isFinite), and if either is not finite or end <=
start return '0h0m0s'; otherwise compute totalMin, hours, minutes and format as
before. Reference: formatDurationStr and timeToMinutes.

In `@frontend/src/pages/class-detail/SessionRow.tsx`:
- Around line 58-60: The same-date reschedule flag is computed
(isSameDateReschedule) but not honored because later conditional checks still
prioritize isRescheduledFrom/To; update the rendering and state precedence in
SessionRow so any conditional branches that check isRescheduledFrom or
isRescheduledTo (including the blocks around the occurrences you noted: the
conditionals at lines handling 63-70, 79-87, 104, 140-148, 173-179) first test
isSameDateReschedule and treat it as a "to" row (apply the blue/to-row styling,
single undo control, and avoid from-row dashed/strike-through UI) before falling
back to isRescheduledFrom/isRescheduledTo; ensure the same precedence is applied
wherever isRescheduledFrom/isRescheduledTo affect className, displayed text, or
action buttons so same-date reschedules consistently render as the "to" state.

In `@frontend/src/pages/class-detail/SessionsTab.tsx`:
- Around line 443-445: SelectedCount currently uses selectedDates.size but bulk
actions operate on selectedUpcomingSessions, causing the toolbar/count to be
wrong after mutations; fix by computing an actionable selection count (e.g.,
const actionableSelectionCount = selectedUpcomingSessions instanceof Set ?
selectedUpcomingSessions.size : new Set([...selectedDates].filter(id =>
selectedUpcomingSessions.has ? selectedUpcomingSessions.has(id) :
selectedUpcomingSessions.includes(id))).size) and pass actionableSelectionCount
to SessionsTabBulkActions as selectedCount, and keep onClearSelection clearing
selection state via setSelectedDates(new Set()) (and any other selection state)
so the UI and actionable set stay in sync; reference SessionsTabBulkActions,
selectedDates, selectedUpcomingSessions, and setSelectedDates.

In `@frontend/src/pages/knowledge-center/ResidentKnowledgeCenter.tsx`:
- Around line 337-338: The new wrapper for ResidentKnowledgeCenter removed
explicit scrolling which caused the missing scrollbar; update the element with
id "knowledge-center-landing" (or the surrounding wrapper used in the
ResidentKnowledgeCenter component) to restore vertical scrolling by adding a
vertical scroll container (e.g., add className/props such as "overflow-y-auto"
and a constrained height like "h-full" or style={{overflowY: 'auto', height:
'100%'}}) so the page regains scrollbars; apply the same change to the other
wrapper instance referenced in the file.

---

Outside diff comments:
In `@frontend/src/pages/class-detail/EnrollResidentsModal.tsx`:
- Around line 64-70: When handling the fetch response in EnrollResidentsModal
(the resp handling block that currently only updates on resp.success &&
resp.type === 'one'), ensure you clear stale conflicts when the response is not
a valid "one" payload by calling setConflictMap(new Map()) (or an empty value
consistent with the ConflictMap type) in the else path; i.e., after the existing
for-loop that builds the Map for resp.data.conflicts, add an else branch that
calls setConflictMap(new Map()) so old conflicts are removed when resp.success
is false or resp.type !== 'one'.

Verify each finding against current code. Fix only still-valid issues, skip the
rest with a brief reason, keep changes minimal, and validate.

Duplicate comments:
In `@frontend/src/pages/class-detail/SessionRow.tsx`:
- Around line 245-267: The action buttons currently check raw flags
(isRescheduledFrom, isCancelledReschedule, isRescheduledTo) and ignore
isSameDateReschedule, so same-date rescheduled rows still show the "from" undo
path; update the JSX conditional logic to give isSameDateReschedule precedence
by adding !isSameDateReschedule to the relevant branches (wrap the
isRescheduledFrom and isCancelledReschedule conditions with isUpcoming &&
!isSameDateReschedule) and ensure any other action branches that should be
suppressed for same-date reschedules also include that check; locate these
conditions in SessionRow.tsx around the Button rendering (symbols:
isSameDateReschedule, isRescheduledFrom, isCancelledReschedule, isRescheduledTo,
isUpcoming, onUndo, onUndoCancel) and modify them accordingly.
- Around line 108-111: The div used in the SessionRow component is only
clickable by mouse; make it keyboard-accessible by adding role="button" and
tabIndex={0} to the outer div, and implement an onKeyDown handler (in the same
component) that calls the existing onClick when the user presses Enter or Space;
keep using getBorderClass() for styling and ensure any aria-label or
aria-expanded is set elsewhere if needed.

In `@frontend/src/pages/knowledge-center/ResidentKnowledgeCenter.tsx`:
- Around line 419-420: The landing container with id "knowledge-center-landing"
lost its vertical scrolling; restore scroll behavior by adding an explicit
vertical overflow (e.g., apply CSS overflow-y: auto or Tailwind class
"overflow-y-auto") to the outer div (the element with id
"knowledge-center-landing") so the Residents view shows scrollbars again; update
either the JSX for that div or the associated CSS rule used by that id.