Add Feedback domain module: public submission flow, admin CRUD, reporting (#7)

Co-authored-by: Patrick Müller <mail@pmueller.me>
Reviewed-on: #7
Co-authored-by: Patrick Mueller <patrick@mueller-patrick.tech>
Co-committed-by: Patrick Mueller <patrick@mueller-patrick.tech>

test/feedback/ratelimit.test.ts

@@ -0,0 +1,20 @@
+import {hashIp} from '../../src/models/feedback/feedback.ratelimit';
+
+describe('hashIp', () => {
+	it('never returns the raw IP', () => {
+		const hash = hashIp('203.0.113.42');
+		expect(hash).not.toContain('203.0.113.42');
+	});
+
+	it('is deterministic for the same input', () => {
+		expect(hashIp('203.0.113.42')).toBe(hashIp('203.0.113.42'));
+	});
+
+	it('differs for different inputs', () => {
+		expect(hashIp('203.0.113.42')).not.toBe(hashIp('203.0.113.43'));
+	});
+
+	it('is a 64-char hex SHA-256 digest', () => {
+		expect(hashIp('203.0.113.42')).toMatch(/^[0-9a-f]{64}$/);
+	});
+});