Migrate date handling from Date to Temporal API

Routine scheduling, health series, service stamps, session expiry, and
date formatting move to native Temporal (Instant / ZonedDateTime in
UTC), with ISO strings kept at DB and chart boundaries. Ambient types
in src/temporal-ambient.d.ts cover the native runtime; no polyfill.
Observable behavior and stored formats are unchanged.

2 files changed, 12 insertions, 4 deletions

diff --git a/src/lib/server/db/groceries.test.ts b/src/lib/server/db/groceries.test.ts
index 143e4da..7fec40b 100644
--- a/src/lib/server/db/groceries.test.ts
+++ b/src/lib/server/db/groceries.test.ts
@@ -29,7 +29,9 @@ describe('groceries add', () => {
 			await db.insert(groceries).values({
 				name,
 				categoryId,
-				createdAt: new Date().toISOString(),
+				createdAt: Temporal.Now.instant().toString({
+					smallestUnit: 'millisecond',
+				}),
 			});
 		}
 	}
@@ -44,7 +46,9 @@ describe('groceries add', () => {
 	});
 
 	it('unchecks an existing checked item instead of creating duplicate', async () => {
-		const now = new Date().toISOString();
+		const now = Temporal.Now.instant().toString({
+			smallestUnit: 'millisecond',
+		});
 		await db
 			.insert(groceries)
 			.values({ name: 'milk', checked: true, createdAt: now });
@@ -56,7 +60,9 @@ describe('groceries add', () => {
 	});
 
 	it('keeps an unchecked item unchanged (already on list)', async () => {
-		const now = new Date().toISOString();
+		const now = Temporal.Now.instant().toString({
+			smallestUnit: 'millisecond',
+		});
 		await db
 			.insert(groceries)
 			.values({ name: 'milk', checked: false, createdAt: now });
diff --git a/src/lib/server/db/ondelete.test.ts b/src/lib/server/db/ondelete.test.ts
index 347bb92..5dcf69e 100644
--- a/src/lib/server/db/ondelete.test.ts
+++ b/src/lib/server/db/ondelete.test.ts
@@ -18,7 +18,9 @@ describe('category delete behavior', () => {
 		await db.insert(groceries).values({
 			name: 'lait',
 			checked: false,
-			createdAt: new Date().toISOString(),
+			createdAt: Temporal.Now.instant().toString({
+				smallestUnit: 'millisecond',
+			}),
 			categoryId: catId,
 		});