feat: support uppercase tag filters (#A-Z) in filter schema

Updates filter-schema.ts validation regex from /^#[a-z]$/ to /^#[a-zA-Z]$/
so uppercase tag filters like #I, #K, #E, #A (used by NIP-22 comment
threading) pass validation. Adds unit test covering NIP-22 uppercase
tag filter acceptance.

Author: CKodidela

src/schemas/filter-schema.ts

@@ -16,7 +16,7 @@ export const filterSchema = z
   .catchall(z.array(z.string().min(1).max(1024)))
   .superRefine((data, ctx) => {
     for (const key of Object.keys(data)) {
-      if (!knownFilterKeys.has(key) && !/^#[a-z]$/.test(key)) {
+      if (!knownFilterKeys.has(key) && !/^#[a-zA-Z]$/.test(key)) {
         ctx.addIssue({
           code: z.ZodIssueCode.custom,
           message: `Unknown key: ${key}`,

test/unit/schemas/filter-schema.spec.ts

@@ -22,6 +22,19 @@ describe('NIP-01', () => {
       }
     })
 
+    it('accepts uppercase tag filters (#A-Z)', () => {
+      const filterWithUppercase = {
+        ...filter,
+        '#I': ['identifier1', 'identifier2'],
+        '#K': ['1111'],
+        '#E': ['aa', 'bb'],
+        '#A': ['10000:pubkey:dtag'],
+      }
+      const result = validateSchema(filterSchema)(filterWithUppercase)
+      expect(result.error).to.be.undefined
+      expect(result.value).to.deep.equal(filterWithUppercase)
+    })
+
     it('returns same filter if filter is valid', () => {
       const result = validateSchema(filterSchema)(filter)