Task #602: quick-note button in schedule fullscreen mode

The amber "ملاحظة / Note" button (#600) lives in the Executive
Meetings page header. The whole header is hidden in fullscreen, so the
quick-note panel — which itself already works in fullscreen — had no
entry point. User had to exit fullscreen, add the note, then re-enter.

Added a floating amber pill next to the existing fullscreen-exit pill
at the top-end of the page. Mirrors the header button exactly:
- Same handler (setQuickNoteOpen + setQuickNoteTrigger).
- Same gating: only Schedule section, hidden while the panel is open
  or while the bulk-actions toolbar is active.
- Same i18n key (executiveMeetings.quickNote.label) — no new strings.
- Same amber palette (bg-amber-100 / border-amber-300 / text-[#0B1E3F])
  with the Plus icon and label.
- Positioned at `top-3 end-14` so it sits inboard of the exit pill
  (`end-3`, w-9) in both LTR (to the left) and RTL (to the right),
  with no overlap.
- `print:hidden`, `data-testid="em-fullscreen-quicknote"`.

Single JSX addition (~36 lines incl. comment) in
artifacts/tx-os/src/pages/executive-meetings.tsx, right after the
exit-fullscreen button. No other files touched. No new state, no new
i18n, no API changes, no dependency changes. Non-fullscreen layout is
untouched. tx-os tsc passes.

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

@@ -1016,6 +1016,43 @@ function ExecutiveMeetingsPageInner() {
           <Minimize2 className="w-5 h-5" />
         </button>
       )}
+      {/* #602: floating amber quick-note pill — the only entry point to
+          the quick-note panel while the page header is hidden in
+          fullscreen. Same gating + handler as the header button at
+          ~L1067 so the two behave identically; positioned inboard of
+          the exit pill (end-14 sits to the left of end-3 in LTR and to
+          the right in RTL). Hidden when the panel is already open or
+          while the bulk-actions toolbar is competing for attention. */}
+      {isFullscreen &&
+        section === "schedule" &&
+        !bulkToolbarActive &&
+        !quickNoteOpen && (
+          <button
+            type="button"
+            onClick={() => {
+              setQuickNoteOpen(true);
+              setQuickNoteTrigger((n) => n + 1);
+            }}
+            data-testid="em-fullscreen-quicknote"
+            aria-label={t(
+              "executiveMeetings.quickNote.label",
+              lang === "ar" ? "ملاحظة" : "Note",
+            )}
+            title={t(
+              "executiveMeetings.quickNote.label",
+              lang === "ar" ? "ملاحظة" : "Note",
+            )}
+            className="fixed top-3 end-14 z-50 inline-flex items-center gap-1.5 rounded-full bg-amber-100 hover:bg-amber-200 border border-amber-300 text-[#0B1E3F] h-9 px-3 text-sm font-medium shadow-lg print:hidden"
+          >
+            <Plus className="w-4 h-4" />
+            <span>
+              {t(
+                "executiveMeetings.quickNote.label",
+                lang === "ar" ? "ملاحظة" : "Note",
+              )}
+            </span>
+          </button>
+        )}
       <header
         ref={headerRef}
         data-testid="em-page-header"