Implemented the calendar view for opportunities

README.md

@@ -1,6 +1,25 @@
 # Opportunities Extension 1.0.2
 
-Browser extension that adds the "Opportunities Extension" shortcut to the permitted Oracle Fusion pages, retrieves opportunities, and displays them in a filterable table.
+Browser extension that adds the "Opportunities Extension" shortcut to the permitted Oracle Fusion pages, retrieves opportunities, and displays them in a filterable table or calendar.
+
+## Opportunity Views
+
+**Visao geral** is the default table view. **Calendario** displays opportunities
+by Close Date (`EffectiveDate`) with month and week views only. Both views share
+Reference, search and all existing filters; switching views does not send requests.
+Events use date-only values without time-zone shifts, stage colors, and a read-only
+detail with an opportunity link and copy button. Invalid or missing dates appear
+in a separate list. Calendar navigation does not change the selected Reference.
+Each day shows a filtered opportunity count, at most two events and an overflow
+link to the remaining events. The grid fits the available height and reduces
+visible events to one or zero when needed to keep every week visible. Missing
+close dates are available in a collapsible list below the calendar.
+Fiscal labels use `FY27-Q2-W19`: June-May fiscal
+years, Sunday-Saturday weeks, and W1 for the week containing June 1. A quarter is
+assigned by the week's Sunday, except the first fiscal week which belongs to Q1.
+
+FullCalendar Standard 6.1.19 is bundled locally under `src/vendor/fullcalendar/`
+with its MIT license. It is initialized only on first use, without a runtime CDN.
 
 ## Development Structure