test: add unit tests for pure logic modules

Add 22 test files covering imager, soundtracks, browser-headers, source-keys (figure/pet/effect), effect-source, plus catalog-translations, catalog-layouts, client-translation-files, translations-utils, and various admin/services/helpers modules. Total test count increases by 120+.

src/lib/trax-format.test.ts

@@ -0,0 +1,69 @@
+import { describe, expect, it } from "vitest";
+import {
+	detectSoundtrackKind,
+	parseTrackSamples,
+	parseTraxChannels,
+	TRAX_TICK_SECONDS,
+} from "./trax-format";
+
+describe("parseTraxChannels", () => {
+	it("returns [] for empty or null tracks", () => {
+		expect(parseTraxChannels("")).toEqual([]);
+		expect(parseTraxChannels(null)).toEqual([]);
+		expect(parseTraxChannels(undefined)).toEqual([]);
+	});
+
+	it("parses per-channel event lists", () => {
+		const channels = parseTraxChannels("1:10,2;0,1:2:5,3");
+		expect(channels).toEqual([
+			{
+				channel: 1,
+				events: [
+					{ sampleId: 10, ticks: 2 },
+					{ sampleId: 0, ticks: 1 },
+				],
+			},
+			{ channel: 2, events: [{ sampleId: 5, ticks: 3 }] },
+		]);
+	});
+
+	it("skips malformed event pairs", () => {
+		const channels = parseTraxChannels("1:10,2;garbage");
+		expect(channels).toEqual([
+			{ channel: 1, events: [{ sampleId: 10, ticks: 2 }] },
+		]);
+	});
+
+	it("drops channels with no valid events", () => {
+		expect(parseTraxChannels("1:junk")).toEqual([]);
+	});
+});
+
+describe("parseTrackSamples", () => {
+	it("collects unique non-zero sample ids, sorted", () => {
+		expect(parseTrackSamples("1:5,1;0,2:2:3,4;5,2")).toEqual([3, 5]);
+	});
+	it("returns [] for silence-only tracks", () => {
+		expect(parseTrackSamples("1:0,3")).toEqual([]);
+	});
+	it("returns [] for empty or unparseable tracks", () => {
+		expect(parseTrackSamples("")).toEqual([]);
+		expect(parseTrackSamples(null)).toEqual([]);
+	});
+});
+
+describe("detectSoundtrackKind", () => {
+	it("classifies a single-sample song as 'single'", () => {
+		expect(detectSoundtrackKind("1:0,24")).toBe("single");
+		expect(detectSoundtrackKind("")).toBe("single");
+	});
+	it("classifies multi-sample tracks as 'composition'", () => {
+		expect(detectSoundtrackKind("1:10,2;20,3")).toBe("composition");
+	});
+});
+
+describe("TRAX_TICK_SECONDS", () => {
+	it("is 2 seconds per tick", () => {
+		expect(TRAX_TICK_SECONDS).toBe(2);
+	});
+});