Task #646: Keep external meeting text navy, not red

Problem: When a meeting was flagged external, the row was tinted red
(pink bg + red number box — desired) but the title cell text and the
attendee list text were also forced to red (#b91c1c), which the user
did not want.

Change (artifacts/tx-os/src/pages/executive-meetings.tsx):
- Meeting title cell: always use navy text (#0B1E3F) instead of switching
  to red on meeting.isExternal.
- Attendee list <ul>: always use navy text (#0B1E3F) instead of switching
  to red on externalText.
- Removed the now-dead `externalText` prop end-to-end (call-site value,
  type declaration, and destructured default) to keep typecheck clean.

Unchanged: the red row tint, red number box, and all external-meeting
behavior (e.g. auto-postpone rules). Internal/virtual meetings unaffected.

Verified: tx-os typecheck passes; HMR applied with no console errors.

artifacts/tx-os/src/pages/executive-meetings.tsx

@@ -4637,7 +4637,7 @@ function MeetingRow({
         return (
           <td
             key="meeting"
-            className={`border border-gray-300 px-3 py-3 align-middle ${meeting.isExternal ? "text-[#b91c1c]" : "text-[#0B1E3F]"} relative group`}
+            className={`border border-gray-300 px-3 py-3 align-middle text-[#0B1E3F] relative group`}
             style={tintedCellStyle(col, true)}
           >
             <EditableCell
@@ -5644,7 +5644,6 @@ function AttendeesCell({
       "executiveMeetings.schedule.newSubheadingAria",
     ),
     meetingId: meeting.id,
-    externalText: Boolean(meeting.isExternal),
   };
 
   if (hasSplit) {
@@ -5847,11 +5846,6 @@ type AttendeeFlowSharedProps = {
   editSubheadingAriaLabel: string;
   newSubheadingAriaLabel: string;
   meetingId: number;
-  // #641: When true, attendee names render in red so the user gets the
-  // same visual cue inside the cell that the row tint already gives at
-  // the row level (external meeting). Group headers and subheadings
-  // keep their own neutral colour — only the names list flips.
-  externalText?: boolean;
   // When true, the trailing "+ عنوان فرعي" <li> at the very end of the
   // flow is NOT rendered. Used by split-mode cells (≥2 attendance
   // groups visible) so the cell shows ONE cell-level "+ عنوان فرعي"
@@ -5903,7 +5897,6 @@ function AttendeeFlow({
   newAriaLabel,
   editSubheadingAriaLabel,
   newSubheadingAriaLabel,
-  externalText = false,
   suppressTrailingSubheadingChip = false,
 }: { items: AttendeeWithIndex[] } & AttendeeFlowSharedProps) {
   const editable = canMutate && !!onSaveAttendeeName;
@@ -6131,7 +6124,7 @@ function AttendeeFlow({
   };
 
   return (
-    <ul className={`flex flex-wrap justify-start items-baseline gap-x-4 gap-y-0.5 ${externalText ? "text-[#b91c1c]" : "text-[#0B1E3F]"} leading-snug`}>
+    <ul className={`flex flex-wrap justify-start items-baseline gap-x-4 gap-y-0.5 text-[#0B1E3F] leading-snug`}>
       {items.flatMap(({ a, i }, listIdx) => {
         const isSub = (a.kind ?? "person") === "subheading";
         const nodes: ReactNode[] = [];