Make Copilot Chat trace a stack frame to a root cause before it proposes a fix

Diagnose this before proposing anything. I do not want a fix suggestion until you have walked
the stack trace below and named a root cause you can point to directly in it.

ERROR
TypeError: Cannot read properties of undefined (reading 'toFixed')

STACK TRACE
at formatRowCount (lib/reports/format.ts:34:18)
at ReportSummary (components/reports/ReportSummary.tsx:19:22)

HOW TO REPRODUCE
Open any report, filter the date range so zero rows match, then view the summary panel.

RELEVANT FILES
lib/reports/format.ts and components/reports/ReportSummary.tsx, pasted below.

WHAT HAS ALREADY BEEN TRIED
Tried adding a loading state around ReportSummary — the crash still happens once loading finishes and zero rows render.

WORK THROUGH THIS IN ORDER
1. Start at the top frame of the stack trace and go down it one frame at a time, stating in this
   codebase specifically — not a generic description of what this error class usually means —
   which line is throwing and what it was doing when it threw.
2. Identify the specific variable, argument, or condition that was actually wrong at that point,
   named precisely, not a category like 'a null reference issue' — name the exact thing and its
   actual value or state at the moment of failure.
3. Trace that wrong value back one more step: where was it supposed to be set correctly, and what
   about Open any report, filter the date range so zero rows match, then view the summary panel. caused it not to be. If the trail goes further back than one step, follow
   it until you reach something that is either clearly the actual origin or clearly outside what
   lib/reports/format.ts and components/reports/ReportSummary.tsx, pasted below. can show you — and say explicitly which of those two you hit.
4. Only now propose the fix, scoped exactly to the root cause identified in steps 2 and 3, as a
   diff — not a broader cleanup of the surrounding code that was not shown to be part of the
   problem.
5. Name one other place in the codebase where the same root cause — the same wrong assumption
   about a value's shape or presence — could plausibly resurface, and say whether that place needs
   the same fix or is already protected against it.

IF Tried adding a loading state around ReportSummary — the crash still happens once loading finishes and zero rows render. DID NOT WORK
Say specifically why the earlier attempt did not fix this, based on what the stack trace above
actually shows — not a vague 'that approach was on the right track but incomplete.' If the earlier
attempt addressed a real but different problem than the one this trace shows, say so plainly
rather than treating it as a partial success.

IF THE TRACE AND FILES GIVEN ARE NOT ENOUGH
Say exactly what additional file, log line, or piece of state you would need to be certain of the
root cause, rather than proposing a fix built on a guess dressed up as a diagnosis.