test: fixed flaky tests by using relative timestamps and palette-agnostic regex

- Replaced fixed calendar timestamps with `minutesAgo()` so beam-store items stay within the 24h working-memory TTL.
- Broadened background-color assertion to match both truecolor (`48;2;`) and 256-palette (`48;5;`) terminals.

packages/coding-agent/test/modes/components/segment-track.test.ts

@@ -36,9 +36,11 @@ describe("renderSegmentTrack", () => {
 
 	it("fills exactly the active segment as a bold chip with a background", () => {
 		const raw = renderSegmentTrack(SEGMENTS, 1);
-		// One filled chip: a single bold run and a single background fill.
+		// One filled chip: a single bold run and a single background fill. The bg
+		// introducer is `48;2;` on truecolor terminals and `48;5;` on 256-palette
+		// ones (CI), so match the palette-agnostic `\x1b[48;` prefix.
 		expect(raw.match(/\x1b\[1m/g)?.length).toBe(1);
-		expect(raw.match(/48;2;/g)?.length).toBe(1);
+		expect(raw.match(/\x1b\[48;/g)?.length).toBe(1);
 		// The active label sits inside the bold run, and the fill is its own accent.
 		expect(raw).toContain("\x1b[1m default \x1b[22m");
 		const activeBg = theme.getFgAnsi("success").replace("\x1b[38;", "\x1b[48;");

packages/mnemosyne/test/beam-store.test.ts

@@ -101,17 +101,21 @@ describe("beam store free functions", () => {
 
 	it("batch remembers items and returns context ordered by global scope, importance, then recency", () => {
 		const beam = makeState();
+		// Timestamps must stay inside the 24h working-memory TTL or trimWorkingMemory
+		// drops them, so anchor them to "now" rather than a fixed (and eventually
+		// stale) calendar date. Order: low-priority oldest, global, high newest.
+		const minutesAgo = (n: number) => new Date(Date.now() - n * 60_000).toISOString();
 		const ids = rememberBatch(
 			beam,
 			[
-				{ content: "Local low priority", importance: 0.1, timestamp: "2026-05-30T00:00:00.000Z" },
+				{ content: "Local low priority", importance: 0.1, timestamp: minutesAgo(3) },
 				{
 					content: "Global rule always include",
 					importance: 0.2,
 					scope: "global",
-					timestamp: "2026-05-30T00:01:00.000Z",
+					timestamp: minutesAgo(2),
 				},
-				{ content: "Local high priority", importance: 0.9, timestamp: "2026-05-30T00:02:00.000Z" },
+				{ content: "Local high priority", importance: 0.9, timestamp: minutesAgo(1) },
 			],
 			{ veracity: "imported" },
 		);