fix(knowledge): reject impossible calendar dates in tag filters

Greptile P1: the date value check was format-only, so 2026-02-30 / 2026-99-99
passed the boundary and then made the document query's ::date cast throw a 500.
Validate real calendar dates by round-tripping the parsed parts.

Author: waleedlatif1

apps/sim/lib/api/contracts/knowledge/documents.test.ts

@@ -93,6 +93,14 @@ describe('parseDocumentTagFiltersParam', () => {
         JSON.stringify([{ tagSlot: 'date1', fieldType: 'date', operator: 'eq', value: 'nope' }])
       )
     ).toThrow()
+    // well-formed but impossible calendar dates (would 500 on ::date)
+    for (const value of ['2026-02-30', '2026-99-99', '2026-13-01', '2026-00-10']) {
+      expect(() =>
+        parseDocumentTagFiltersParam(
+          JSON.stringify([{ tagSlot: 'date1', fieldType: 'date', operator: 'eq', value }])
+        )
+      ).toThrow()
+    }
     // non-boolean value on a boolean field
     expect(() =>
       parseDocumentTagFiltersParam(

apps/sim/lib/knowledge/filters/types.ts

@@ -193,6 +193,19 @@ export function getOperatorsForFieldType(fieldType: FilterFieldType): OperatorIn
 /** Wire format for a date filter value (`YYYY-MM-DD`). */
 const DATE_ONLY_VALUE = /^\d{4}-\d{2}-\d{2}$/
 
+/**
+ * Whether a `YYYY-MM-DD` string is a real calendar date. The format regex alone
+ * still admits impossible dates (`2026-02-30`, `2026-99-99`) that pass the
+ * boundary and then make the document query's `::date` cast throw a 500; this
+ * round-trips the parsed parts to reject them.
+ */
+function isRealCalendarDate(value: string): boolean {
+  if (!DATE_ONLY_VALUE.test(value)) return false
+  const [year, month, day] = value.split('-').map(Number)
+  const date = new Date(year, month - 1, day)
+  return date.getFullYear() === year && date.getMonth() === month - 1 && date.getDate() === day
+}
+
 /**
  * Whether a raw filter value is usable for the given field type. Shared source
  * of truth so the API boundary can reject unusable values (e.g. `"abc"` for a
@@ -208,7 +221,7 @@ export function isValidFilterValue(fieldType: FilterFieldType, value: unknown):
       if (typeof value === 'number') return Number.isFinite(value)
       return typeof value === 'string' && value.trim() !== '' && Number.isFinite(Number(value))
     case 'date':
-      return typeof value === 'string' && DATE_ONLY_VALUE.test(value)
+      return typeof value === 'string' && isRealCalendarDate(value)
     case 'boolean':
       return (
         typeof value === 'boolean' ||