fix: remove special character requirement from stream keys (#4754)

Some broadcasting software (e.g., Prism Live Studio) strips special
characters from stream keys, making Owncast-generated keys incompatible.

Changes:
- Create separate STREAM_KEY_COMPLEXITY_RULES without special char requirement
- Update generateRndKey() to only use alphanumeric characters
- Keep PASSWORD_COMPLEXITY_RULES unchanged for admin password security
- Update tooltip text to reflect new requirements
- Add comprehensive tests for stream key generation

Fixes #4690

Co-authored-by: Claude Opus 4.5 <noreply@anthropic.com>

web/tests/streamkeys.test.ts

@@ -1,10 +1,23 @@
 import { generateRndKey } from '../components/admin/config/server/StreamKeys';
+import { REGEX_STREAM_KEY } from '../utils/config-constants';
 
 describe('generateRndKey', () => {
-  test('should generate a key that matches the regular expression', () => {
+  test('should generate a key that matches the stream key regex', () => {
     const key = generateRndKey();
-    const regex = /^(?=.*?[A-Z])(?=.*?[a-z])(?=.*?[0-9])(?=.*?[!@#$^&*]).{8,192}$/;
-    expect(regex.test(key)).toBe(true);
+    // Use the same regex constant that the implementation uses
+    expect(REGEX_STREAM_KEY.test(key)).toBe(true);
+  });
+
+  test('should only contain alphanumeric characters (no special characters for broadcasting software compatibility)', () => {
+    const key = generateRndKey();
+    // Keys should be purely alphanumeric for compatibility with broadcasting software
+    expect(key).toMatch(/^[a-zA-Z0-9]+$/);
+  });
+
+  test('should not contain dashes', () => {
+    const key = generateRndKey();
+    // Dashes are explicitly forbidden as they can break RTMP URL parsing
+    expect(key).not.toContain('-');
   });
 
   test('returns a string', () => {
@@ -23,4 +36,20 @@ describe('generateRndKey', () => {
     const key2 = generateRndKey();
     expect(key1).not.toBe(key2);
   });
+
+  test('should contain at least one uppercase letter, one lowercase letter, and one digit', () => {
+    const key = generateRndKey();
+    expect(key).toMatch(/[A-Z]/); // has uppercase
+    expect(key).toMatch(/[a-z]/); // has lowercase
+    expect(key).toMatch(/[0-9]/); // has digit
+  });
+
+  test('should consistently generate valid keys across multiple invocations', () => {
+    // Generate multiple keys to ensure consistency
+    for (let i = 0; i < 10; i++) {
+      const key = generateRndKey();
+      expect(REGEX_STREAM_KEY.test(key)).toBe(true);
+      expect(key).toMatch(/^[a-zA-Z0-9]+$/);
+    }
+  });
 });