@@ -3,7 +3,9 @@ const { readFileSync, existsSync, mkdirSync, createWriteStream } = require('fs')
 const { spawn } = require('child_process')
 
 function parseSvelteCheckLog(logContent) {
-  const lines = logContent.split('\n')
+  // Human output includes ANSI colors, even when redirected to a log file.
+  // Strip them before looking for "Error:" so failed checks report the errors.
+  const lines = logContent.replace(/\x1b\[[0-9;]*m/g, '').split('\n')
   const errors = []
   let currentError = null
 
 
@@ -141,3 +141,29 @@ describe('time-scale — secondary label (year/month supra row)', () => {
     void DAY
   })
 })
+
+describe('time-scale locale', () => {
+  const origin = Date.UTC(2026, 0, 1)
+
+  it.each(['en', 'ru', 'de', 'ja'])('formats day and month labels using %s', (locale) => {
+    const expected = new Intl.DateTimeFormat(locale, { month: 'short', timeZone: 'UTC' }).format(origin)
+    expect(createTimeScale('day', origin, undefined, { locale }).ticks([origin, origin])[0].secondaryLabel).toBe(
+      expected
+    )
+    expect(createTimeScale('month', origin, undefined, { locale }).ticks([origin, origin])[0].label).toBe(expected)
+  })
+
+  it('accepts translated week and quarter labels without changing geometry', () => {
+    const labels = {
+      locale: 'ru',
+      weekLabel: (week: number) => `Нед. ${week}`,
+      quarterLabel: (quarter: number) => `Кв. ${quarter}`
+    }
+    const week = createTimeScale('week', origin, 14, labels)
+    const first = week.ticks([origin, origin + 7 * DAY_MS])[0]
+    expect(first.label).toBe('Нед. 2')
+    expect(first.date).toBe(Date.UTC(2026, 0, 5))
+    expect(week.toX(first.date)).toBe(56)
+    expect(createTimeScale('quarter', origin, undefined, labels).ticks([origin, origin])[0].label).toBe('Кв. 1')
+  })
+})
@@ -16,6 +16,7 @@ const ALL: ToolbarTier[] = [...TOOLBAR_TIERS]
 // One easy-to-reason-about width per tier.
 const W: Record<ToolbarTier, number> = {
   group: 100,
+  color: 80,
   nav: 200,
   date: 150,
   zoom: 120,
@@ -39,24 +40,31 @@ describe('computeToolbarOverflow', () => {
   })
 
   it('keeps everything inline when it fits exactly', () => {
-    // 100+200+150+120+60+90 = 720, plus five gaps = 740
-    const r = computeToolbarOverflow(ALL, W, 740, GAP, MORE)
+    // 100+80+200+150+120+60+90 = 800, plus six gaps = 824
+    const r = computeToolbarOverflow(ALL, W, 824, GAP, MORE)
     expect(r.hidden).toEqual([])
     expect(r.visible).toEqual(ALL)
   })
 
   it('collapses the least important tier first', () => {
-    const r = computeToolbarOverflow(ALL, W, 739, GAP, MORE)
+    const r = computeToolbarOverflow(ALL, W, 823, GAP, MORE)
     expect(r.hidden).toEqual(['savedview'])
-    expect(r.visible).toEqual(['group', 'nav', 'date', 'zoom', 'undo'])
+    expect(r.visible).toEqual(['group', 'color', 'nav', 'date', 'zoom', 'undo'])
   })
 
   it('collapses further tiers in TOOLBAR_COLLAPSE_ORDER as space shrinks', () => {
-    expect(computeToolbarOverflow(ALL, W, 600, GAP, MORE).hidden).toEqual(['date', 'savedview'])
-    expect(computeToolbarOverflow(ALL, W, 450, GAP, MORE).hidden).toEqual(['group', 'date', 'savedview'])
-    expect(computeToolbarOverflow(ALL, W, 400, GAP, MORE).hidden).toEqual(['group', 'date', 'undo', 'savedview'])
+    expect(computeToolbarOverflow(ALL, W, 600, GAP, MORE).hidden).toEqual(['color', 'date', 'savedview'])
+    expect(computeToolbarOverflow(ALL, W, 450, GAP, MORE).hidden).toEqual(['group', 'color', 'date', 'savedview'])
+    expect(computeToolbarOverflow(ALL, W, 400, GAP, MORE).hidden).toEqual([
+      'group',
+      'color',
+      'date',
+      'undo',
+      'savedview'
+    ])
     expect(computeToolbarOverflow(ALL, W, 300, GAP, MORE).hidden).toEqual([
       'group',
+      'color',
       'date',
       'zoom',
       'undo',
@@ -71,7 +79,7 @@ describe('computeToolbarOverflow', () => {
   })
 
   it('never drops a tier — visible + hidden is always the input set', () => {
-    for (const available of [-1, 0, 30, 120, 300, 500, 740, 2000]) {
+    for (const available of [-1, 0, 30, 120, 300, 500, 824, 2000]) {
       const r = computeToolbarOverflow(ALL, W, available, GAP, MORE)
       expect([...r.visible, ...r.hidden].sort()).toEqual([...ALL].sort())
     }
@@ -83,6 +91,13 @@ describe('computeToolbarOverflow', () => {
     expect(r.hidden).toEqual(ALL.filter((t) => r.hidden.includes(t)))
   })
 
+  it('keeps grouping inline when only one of the two view controls fits', () => {
+    const present: ToolbarTier[] = ['group', 'color', 'nav', 'zoom', 'undo']
+    const r = computeToolbarOverflow(present, W, 510, GAP, 0)
+    expect(r.visible).toEqual(['group', 'nav', 'zoom', 'undo'])
+    expect(r.hidden).toEqual(['color'])
+  })
+
   it('ignores tiers that are not present', () => {
     const present: ToolbarTier[] = ['nav', 'zoom']
     // nav(200) + zoom(120) + gap = 324 > 240; nav alone plus the "…" trigger
 
@@ -45,7 +45,22 @@ export interface TimeScale {
   ticks: (range: [number, number]) => Tick[]
 }
 
-export function createTimeScale (zoom: ZoomLevel, origin: number, pxPerDayOverride?: number): TimeScale {
+/** Presentation settings supplied by the host application's active language. */
+export interface TimeScaleLocale {
+  locale?: string
+  weekLabel?: (week: number) => string
+  quarterLabel?: (quarter: number) => string
+}
+
+export function createTimeScale (
+  zoom: ZoomLevel,
+  origin: number,
+  pxPerDayOverride?: number,
+  labels: TimeScaleLocale = {}
+): TimeScale {
+  const locale = labels.locale ?? 'en'
+  const weekLabel = labels.weekLabel ?? ((week: number) => `W${week}`)
+  const quarterLabel = labels.quarterLabel ?? ((quarter: number) => `Q${quarter}`)
   const pxPerDay = pxPerDayOverride ?? PX_PER_DAY[zoom]
   const originSnapped = snapToUtcMidnight(origin)
 
@@ -71,7 +86,7 @@ export function createTimeScale (zoom: ZoomLevel, origin: number, pxPerDayOverri
           const m = d.getUTCMonth()
           let secondary: string | undefined
           if (first || m !== lastMonth) {
-            secondary = d.toLocaleString(undefined, { month: 'short', timeZone: 'UTC' })
+            secondary = d.toLocaleString(locale, { month: 'short', timeZone: 'UTC' })
             lastMonth = m
             first = false
           }
@@ -106,7 +121,7 @@ export function createTimeScale (zoom: ZoomLevel, origin: number, pxPerDayOverri
           }
           result.push({
             date: cursor,
-            label: `W${isoWeekNumber(c)}`,
+            label: weekLabel(isoWeekNumber(c)),
             level: isFirstWeekOfMonth ? 'major' : 'minor',
             secondaryLabel: secondary
           })
@@ -135,7 +150,7 @@ export function createTimeScale (zoom: ZoomLevel, origin: number, pxPerDayOverri
           }
           result.push({
             date: cursor,
-            label: c.toLocaleString(undefined, { month: 'short', timeZone: 'UTC' }),
+            label: c.toLocaleString(locale, { month: 'short', timeZone: 'UTC' }),
             level: c.getUTCMonth() === 0 ? 'major' : 'minor',
             secondaryLabel: secondary
           })
@@ -170,7 +185,7 @@ export function createTimeScale (zoom: ZoomLevel, origin: number, pxPerDayOverri
           }
           result.push({
             date: cursor,
-            label: `Q${qNum}`,
+            label: quarterLabel(qNum),
             level: qNum === 1 ? 'major' : 'minor',
             secondaryLabel: secondary
           })
 
@@ -28,7 +28,7 @@
  * that collapses as a whole; splitting e.g. the date-navigation into single
  * buttons would leave a half-usable control group behind.
  */
-export const TOOLBAR_TIERS = ['group', 'nav', 'date', 'zoom', 'undo', 'savedview'] as const
+export const TOOLBAR_TIERS = ['group', 'color', 'nav', 'date', 'zoom', 'undo', 'savedview'] as const
 export type ToolbarTier = (typeof TOOLBAR_TIERS)[number]
 
 /**
@@ -37,12 +37,21 @@ export type ToolbarTier = (typeof TOOLBAR_TIERS)[number]
  * - `savedview` is a passive "modified" indicator plus its update button; the
  *   same action is reachable from the More-actions menu.
  * - `date` (jump-to-date) duplicates what panning and the nav buttons do.
- * - `group` (group-by / colour-by) is view configuration, not navigation.
+ * - `color` is cosmetic; keep `group` visible longer because it changes the
+ *   layout of the issue list and chart.
  * - `undo` matters while editing, but the keyboard shortcuts stay live.
  * - `zoom` and `nav` are the two controls a Gantt is unusable without, so
  *   they are the last to go.
  */
-export const TOOLBAR_COLLAPSE_ORDER: readonly ToolbarTier[] = ['savedview', 'date', 'group', 'undo', 'zoom', 'nav']
+export const TOOLBAR_COLLAPSE_ORDER: readonly ToolbarTier[] = [
+  'savedview',
+  'date',
+  'color',
+  'group',
+  'undo',
+  'zoom',
+  'nav'
+]
 
 /**
  * Width assumed for a tier that has never been measured. Deliberately
 
@@ -315,7 +315,19 @@
     "SearchEmptyTitle": "Pro „{query}\" nebyly nalezeny žádné úkoly",
     "SearchEmptyActiveFilters": "Aktivní filtry: {filters}",
     "SearchEmptyClearFilters": "Hledat bez filtrů",
-    "SearchEmptyAllProjects": "Hledat ve všech projektech"
+    "SearchEmptyAllProjects": "Hledat ve všech projektech",
+    "GanttWeekLabel": "T{week}",
+    "GanttQuarterLabel": "Q{quarter}",
+    "GanttWithoutDates": "{count} bez dat",
+    "GanttDates": "Data",
+    "GanttZoomLabel": "Přiblížení",
+    "GanttSetDates": "Nastavit data",
+    "GanttNoScheduledTasks": "Žádné naplánované úkoly",
+    "GanttTodayAlreadyVisible": "Dnešek je již zobrazen",
+    "GanttVisibleRange": "Rozsah",
+    "GanttNotScheduled": "Nenaplánováno",
+    "GanttMissingStartDates": "{count} úkolů nemá datum zahájení.",
+    "GanttSetDatesHint": "Nastavte u úkolu datum zahájení a termín dokončení, aby se zobrazil v časové ose."
   },
   "status": {}
 }
@@ -358,6 +358,8 @@
     "GanttJumpToDate": "Zu Datum springen",
     "GanttZoomDay": "Tag",
     "GanttZoomWeek": "Woche",
+    "GanttWeekLabel": "KW{week}",
+    "GanttQuarterLabel": "Q{quarter}",
     "GanttZoomMonth": "Monat",
     "GanttZoomQuarter": "Quartal",
     "GanttZoomCustom": "Benutzerdefiniert",
@@ -563,7 +565,16 @@
     "SearchEmptyTitle": "Keine Treffer für \"{query}\"",
     "SearchEmptyActiveFilters": "Aktive Filter: {filters}",
     "SearchEmptyClearFilters": "Suche ohne Filter",
-    "SearchEmptyAllProjects": "In allen Projekten suchen"
+    "SearchEmptyAllProjects": "In allen Projekten suchen",
+    "GanttWithoutDates": "{count} ohne Daten",
+    "GanttDates": "Termine",
+    "GanttSetDates": "Daten festlegen",
+    "GanttNoScheduledTasks": "Keine geplanten Aufgaben",
+    "GanttTodayAlreadyVisible": "Heute ist bereits sichtbar",
+    "GanttVisibleRange": "Zeitraum",
+    "GanttNotScheduled": "Nicht geplant",
+    "GanttMissingStartDates": "Für {count} Aufgaben ist kein Startdatum festgelegt.",
+    "GanttSetDatesHint": "Legen Sie für ein Issue Start- und Fälligkeitsdatum fest, damit es auf der Zeitachse erscheint."
   },
   "status": {}
 }
@@ -344,6 +344,8 @@
     "GanttJumpToDate": "Jump to date",
     "GanttZoomDay": "Day",
     "GanttZoomWeek": "Week",
+    "GanttWeekLabel": "W{week}",
+    "GanttQuarterLabel": "Q{quarter}",
     "GanttZoomMonth": "Month",
     "GanttZoomQuarter": "Quarter",
     "GanttZoomCustom": "Custom",
@@ -563,7 +565,16 @@
     "SearchEmptyTitle": "No issues found for \"{query}\"",
     "SearchEmptyActiveFilters": "Active filters: {filters}",
     "SearchEmptyClearFilters": "Search without filters",
-    "SearchEmptyAllProjects": "Search in all projects"
+    "SearchEmptyAllProjects": "Search in all projects",
+    "GanttWithoutDates": "{count} without dates",
+    "GanttDates": "Dates",
+    "GanttSetDates": "Set dates",
+    "GanttNoScheduledTasks": "No scheduled tasks",
+    "GanttTodayAlreadyVisible": "Today is already in view",
+    "GanttVisibleRange": "Range",
+    "GanttNotScheduled": "Not scheduled",
+    "GanttMissingStartDates": "{count} issues have no start date.",
+    "GanttSetDatesHint": "Set start and due dates in an issue to show its timeline."
   },
   "status": {}
 }
@@ -308,7 +308,19 @@
     "SearchEmptyTitle": "No se encontraron tareas para \"{query}\"",
     "SearchEmptyActiveFilters": "Filtros activos: {filters}",
     "SearchEmptyClearFilters": "Buscar sin filtros",
-    "SearchEmptyAllProjects": "Buscar en todos los proyectos"
+    "SearchEmptyAllProjects": "Buscar en todos los proyectos",
+    "GanttWeekLabel": "S{week}",
+    "GanttQuarterLabel": "T{quarter}",
+    "GanttWithoutDates": "{count} sin fechas",
+    "GanttDates": "Fechas",
+    "GanttZoomLabel": "Zoom",
+    "GanttSetDates": "Establecer fechas",
+    "GanttNoScheduledTasks": "No hay tareas programadas",
+    "GanttTodayAlreadyVisible": "Hoy ya está visible",
+    "GanttVisibleRange": "Intervalo",
+    "GanttNotScheduled": "Sin programar",
+    "GanttMissingStartDates": "{count} tareas no tienen fecha de inicio.",
+    "GanttSetDatesHint": "Establece las fechas de inicio y vencimiento de una tarea para mostrarla en la línea de tiempo."
   },
   "status": {}
 }