fix: parse SQLite timestamps as UTC, not local time

SQLite datetime('now') returns 'YYYY-MM-DD HH:MM:SS' with no timezone
marker. JS was treating this as local time, so timestamps showed the
correct UTC digits but with the local TZ abbreviation attached (e.g.
'7:15 PM EDT' when the real local time was '3:15 PM EDT').

Add parseUtc() which appends 'Z' before parsing any string that has no
existing timezone marker, ensuring JS always treats them as UTC before
the display-timezone conversion is applied.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

tests/helpers.test.js

@@ -58,16 +58,22 @@ describe('esc', () => {
 
 // ── fmtDate() ─────────────────────────────────────────────────────────────────
 
-function fmtDate(d) {
+function parseUtc(d) {
+  if (typeof d !== 'string') return new Date(d)
+  const hasZone = d.endsWith('Z') || /[+-]\d{2}:\d{2}$/.test(d)
+  return new Date(hasZone ? d : d.replace(' ', 'T') + 'Z')
+}
+
+function fmtDate(d, tz = 'UTC') {
   if (!d) return '—'
   try {
-    return new Date(d).toLocaleDateString('en-US', { year: 'numeric', month: 'short', day: 'numeric' })
+    return parseUtc(d).toLocaleDateString('en-US', { year: 'numeric', month: 'short', day: 'numeric', timeZone: tz })
   } catch (e) { return d }
 }
 
 describe('fmtDate', () => {
   it('formats a valid ISO date string', () => {
-    const result = fmtDate('2024-03-15T00:00:00')
+    const result = fmtDate('2024-03-15T12:00:00Z')
     expect(result).toMatch(/Mar/)
     expect(result).toMatch(/15/)
     expect(result).toMatch(/2024/)
@@ -91,7 +97,7 @@ describe('fmtDate', () => {
 function fmtDateFull(d, tz = 'UTC') {
   if (!d) return '—'
   try {
-    return new Date(d).toLocaleString('en-US', {
+    return parseUtc(d).toLocaleString('en-US', {
       year: 'numeric', month: 'short', day: 'numeric',
       hour: '2-digit', minute: '2-digit',
       timeZone: tz, timeZoneName: 'short',
@@ -118,6 +124,12 @@ describe('fmtDateFull', () => {
     expect(result).toMatch(/EDT/)
   })
 
+  it('treats SQLite-format timestamps (space, no Z) as UTC', () => {
+    // SQLite datetime('now') → 'YYYY-MM-DD HH:MM:SS', no timezone marker.
+    // Must parse identically to the same moment expressed as ISO UTC.
+    expect(fmtDateFull('2024-03-15 18:30:00', 'UTC')).toBe(fmtDateFull('2024-03-15T18:30:00Z', 'UTC'))
+  })
+
   it('returns — for null', () => {
     expect(fmtDateFull(null)).toBe('—')
   })