feat(tracker): add Gantt scheduling schema (startDate + IssueRelation)

Schema-only foundation for the upcoming Gantt-chart view in tracker.
No UI in this PR.

Changes:
- Issue.startDate: Timestamp | null (interface + IssueDraft + @Prop with @Index)
- Milestone.startDate: Timestamp | null (interface + @Prop, reusing the
  existing tracker.string.StartDate IntlString)
- New DependencyKind type ('finish-to-start' | 'start-to-start' |
  'finish-to-finish' | 'start-to-finish')
- New IssueRelation AttachedDoc class with kind: DependencyKind, signed
  lag: number — registered in models/tracker via TIssueRelation
- 7 new IntlString keys: IssueStartDate, GanttDependency,
  GanttDependency{FinishToStart,StartToStart,FinishToFinish,StartToFinish},
  GanttLag — all 13 locales updated
- Cross-plugin literal updates in importer + github sync to satisfy the new
  required Issue.startDate / Milestone.startDate fields:
  - packages/importer/src/importer/importer.ts: AttachedData<Issue> literal
  - services/github/pod-github/src/sync/issueBase.ts: 'startDate' added to
    GithubIssueData Omit list (github sync does not own scheduling)
  - services/github/pod-github/src/sync/issues.ts + pullrequests.ts:
    AttachedData<Issue|GithubPullRequest> literals

Out of scope (deferred to follow-up PRs):
- UI for Gantt view, drag/resize, dependency editor, critical path
- blockedBy → IssueRelation migration (ships atomically with the writer
  redirect in the dependency-UI PR)
- LinkIssues permission (tracker uses forbid-style permissions; needs
  maintainer discussion)
- Activity-feed wiring for IssueRelation (needs a producer to test against)
- IssueTemplate.startDate (template propagation semantics undecided)

Signed-off-by: Michael Uray <michaeluray@users.noreply.github.com>

models/tracker/src/index.ts

@@ -39,6 +39,7 @@ import {
   TClassicProjectTypeData,
   TComponent,
   TIssue,
+  TIssueRelation,
   TIssueStatus,
   TIssueTemplate,
   TIssueTypeData,
@@ -441,6 +442,7 @@ export function createModel (builder: Builder): void {
     TProject,
     TComponent,
     TIssue,
+    TIssueRelation,
     TIssueTemplate,
     TIssueStatus,
     TTypeIssuePriority,

models/tracker/src/types.ts

@@ -58,10 +58,12 @@ import time, { type ToDo } from '@hcengineering/time'
 import {
   type ProjectTargetPreference,
   type Component,
+  type DependencyKind,
   type Issue,
   type IssueChildInfo,
   type IssueParentInfo,
   type IssuePriority,
+  type IssueRelation,
   type IssueStatus,
   type IssueTemplate,
   type IssueTemplateChild,
@@ -233,6 +235,10 @@ export class TIssue extends TTask implements Issue {
   @ReadOnly()
   declare space: Ref<Project>
 
+  @Prop(TypeDate(DateRangeMode.DATETIME), tracker.string.IssueStartDate)
+  @Index(IndexKind.Indexed)
+  declare startDate: Timestamp | null
+
   @Prop(TypeDate(DateRangeMode.DATETIME), tracker.string.DueDate)
   declare dueDate: Timestamp | null
 
@@ -340,6 +346,26 @@ export class TTimeSpendReport extends TAttachedDoc implements TimeSpendReport {
   @Prop(TypeString(), tracker.string.TimeSpendReportDescription)
     description!: string
 }
+
+/**
+ * @public
+ */
+@Model(tracker.class.IssueRelation, core.class.AttachedDoc, DOMAIN_TRACKER)
+@UX(tracker.string.GanttDependency, tracker.icon.Issue)
+export class TIssueRelation extends TAttachedDoc implements IssueRelation {
+  @Prop(TypeRef(tracker.class.Issue), tracker.string.Issue)
+  declare attachedTo: Ref<Issue>
+
+  @Prop(TypeRef(tracker.class.Issue), tracker.string.Issue)
+  @Index(IndexKind.Indexed)
+    target!: Ref<Issue>
+
+  @Prop(TypeString(), tracker.string.GanttDependency)
+    kind!: DependencyKind
+
+  @Prop(TypeNumber(), tracker.string.GanttLag)
+    lag!: number
+}
 /**
  * @public
  */
@@ -389,6 +415,9 @@ export class TMilestone extends TDoc implements Milestone {
   @Prop(Collection(attachment.class.Attachment), attachment.string.Attachments, { shortLabel: attachment.string.Files })
     attachments?: number
 
+  @Prop(TypeDate(), tracker.string.StartDate)
+    startDate!: Timestamp | null
+
   @Prop(TypeDate(), tracker.string.TargetDate)
     targetDate!: Timestamp
 

packages/importer/src/importer/importer.ts

@@ -591,6 +591,7 @@ export class WorkspaceImporter {
       rank,
       comments: issue.comments?.length ?? 0,
       subIssues: issue.subdocs.length,
+      startDate: null,
       dueDate: null,
       parents: parentsInfo,
       remainingTime,

plugins/tracker-assets/lang/cs.json

@@ -115,6 +115,13 @@
     "NoAssignee": "Bez přiřazení",
     "LastUpdated": "Poslední aktualizace",
     "DueDate": "Datum splnění",
+    "IssueStartDate": "Datum zahájení",
+    "GanttDependency": "Dependency",
+    "GanttDependencyFinishToFinish": "Finish to finish",
+    "GanttDependencyFinishToStart": "Finish to start",
+    "GanttDependencyStartToFinish": "Start to finish",
+    "GanttDependencyStartToStart": "Start to start",
+    "GanttLag": "Lag",
     "Manual": "Manuální",
     "All": "Vše",
     "PastWeek": "Minulý týden",

plugins/tracker-assets/lang/de.json

@@ -125,6 +125,13 @@
     "NoAssignee": "Nicht zugewiesen",
     "LastUpdated": "Zuletzt aktualisiert",
     "DueDate": "Fälligkeitsdatum",
+    "IssueStartDate": "Startdatum",
+    "GanttDependency": "Abhängigkeit",
+    "GanttDependencyFinishToFinish": "Ende zu Ende",
+    "GanttDependencyFinishToStart": "Ende zu Anfang",
+    "GanttDependencyStartToFinish": "Anfang zu Ende",
+    "GanttDependencyStartToStart": "Anfang zu Anfang",
+    "GanttLag": "Verzögerung",
     "Manual": "Manuell",
     "All": "Alle",
     "PastWeek": "Letzte Woche",

plugins/tracker-assets/lang/en.json

@@ -125,6 +125,13 @@
     "NoAssignee": "No assignee",
     "LastUpdated": "Last updated",
     "DueDate": "Due date",
+    "IssueStartDate": "Start date",
+    "GanttDependency": "Dependency",
+    "GanttDependencyFinishToFinish": "Finish to finish",
+    "GanttDependencyFinishToStart": "Finish to start",
+    "GanttDependencyStartToFinish": "Start to finish",
+    "GanttDependencyStartToStart": "Start to start",
+    "GanttLag": "Lag",
     "Manual": "Manual",
     "All": "All",
     "PastWeek": "Past week",

plugins/tracker-assets/lang/es.json

@@ -123,6 +123,13 @@
     "NoAssignee": "Sin asignar",
     "LastUpdated": "Última actualización",
     "DueDate": "Fecha de vencimiento",
+    "IssueStartDate": "Fecha de inicio",
+    "GanttDependency": "Dependency",
+    "GanttDependencyFinishToFinish": "Finish to finish",
+    "GanttDependencyFinishToStart": "Finish to start",
+    "GanttDependencyStartToFinish": "Start to finish",
+    "GanttDependencyStartToStart": "Start to start",
+    "GanttLag": "Lag",
     "Manual": "Manual",
     "All": "Todos",
     "PastWeek": "Semana pasada",

plugins/tracker-assets/lang/fr.json

@@ -123,6 +123,13 @@
     "NoAssignee": "Non assigné",
     "LastUpdated": "Dernière mise à jour",
     "DueDate": "Date d'échéance",
+    "IssueStartDate": "Date de début",
+    "GanttDependency": "Dependency",
+    "GanttDependencyFinishToFinish": "Finish to finish",
+    "GanttDependencyFinishToStart": "Finish to start",
+    "GanttDependencyStartToFinish": "Start to finish",
+    "GanttDependencyStartToStart": "Start to start",
+    "GanttLag": "Lag",
     "Manual": "Manuel",
     "All": "Tous",
     "PastWeek": "La semaine passée",

plugins/tracker-assets/lang/it.json

@@ -123,6 +123,13 @@
     "NoAssignee": "Nessun assegnatario",
     "LastUpdated": "Ultimo aggiornamento",
     "DueDate": "Data di scadenza",
+    "IssueStartDate": "Data di inizio",
+    "GanttDependency": "Dependency",
+    "GanttDependencyFinishToFinish": "Finish to finish",
+    "GanttDependencyFinishToStart": "Finish to start",
+    "GanttDependencyStartToFinish": "Start to finish",
+    "GanttDependencyStartToStart": "Start to start",
+    "GanttLag": "Lag",
     "Manual": "Manuale",
     "All": "Tutti",
     "PastWeek": "Settimana scorsa",

plugins/tracker-assets/lang/ja.json

@@ -123,6 +123,13 @@
     "NoAssignee": "担当者なし",
     "LastUpdated": "最終更新日",
     "DueDate": "期日",
+    "IssueStartDate": "開始日",
+    "GanttDependency": "Dependency",
+    "GanttDependencyFinishToFinish": "Finish to finish",
+    "GanttDependencyFinishToStart": "Finish to start",
+    "GanttDependencyStartToFinish": "Start to finish",
+    "GanttDependencyStartToStart": "Start to start",
+    "GanttLag": "Lag",
     "Manual": "手動",
     "All": "すべて",
     "PastWeek": "先週",

plugins/tracker-assets/lang/ko.json

@@ -123,6 +123,13 @@
         "NoAssignee": "담당자 없음",
         "LastUpdated": "최근 업데이트",
         "DueDate": "마감일",
+        "IssueStartDate": "시작일",
+        "GanttDependency": "Dependency",
+        "GanttDependencyFinishToFinish": "Finish to finish",
+        "GanttDependencyFinishToStart": "Finish to start",
+        "GanttDependencyStartToFinish": "Start to finish",
+        "GanttDependencyStartToStart": "Start to start",
+        "GanttLag": "Lag",
         "Manual": "수동",
         "All": "전체",
         "PastWeek": "지난주",

plugins/tracker-assets/lang/pt-br.json

@@ -123,6 +123,13 @@
     "NoAssignee": "Sem atribuição",
     "LastUpdated": "Última atualização",
     "DueDate": "Data de vencimento",
+    "IssueStartDate": "Data de início",
+    "GanttDependency": "Dependency",
+    "GanttDependencyFinishToFinish": "Finish to finish",
+    "GanttDependencyFinishToStart": "Finish to start",
+    "GanttDependencyStartToFinish": "Start to finish",
+    "GanttDependencyStartToStart": "Start to start",
+    "GanttLag": "Lag",
     "Manual": "Manual",
     "All": "Todos",
     "PastWeek": "Semana passada",

plugins/tracker-assets/lang/pt.json

@@ -123,6 +123,13 @@
     "NoAssignee": "Sem atribuição",
     "LastUpdated": "Última atualização",
     "DueDate": "Data de vencimento",
+    "IssueStartDate": "Data de início",
+    "GanttDependency": "Dependency",
+    "GanttDependencyFinishToFinish": "Finish to finish",
+    "GanttDependencyFinishToStart": "Finish to start",
+    "GanttDependencyStartToFinish": "Start to finish",
+    "GanttDependencyStartToStart": "Start to start",
+    "GanttLag": "Lag",
     "Manual": "Manual",
     "All": "Todos",
     "PastWeek": "Semana passada",

plugins/tracker-assets/lang/ru.json

@@ -125,6 +125,13 @@
     "NoAssignee": "Нет исполнителя",
     "LastUpdated": "Последнее обновление",
     "DueDate": "Срок",
+    "IssueStartDate": "Дата начала",
+    "GanttDependency": "Dependency",
+    "GanttDependencyFinishToFinish": "Finish to finish",
+    "GanttDependencyFinishToStart": "Finish to start",
+    "GanttDependencyStartToFinish": "Start to finish",
+    "GanttDependencyStartToStart": "Start to start",
+    "GanttLag": "Lag",
     "Manual": "Пользовательский",
     "All": "Все",
     "PastWeek": "Предыдущая неделя",

plugins/tracker-assets/lang/tr.json

@@ -123,6 +123,13 @@
     "NoAssignee": "Atanan yok",
     "LastUpdated": "Son güncelleme",
     "DueDate": "Bitiş tarihi",
+    "IssueStartDate": "Başlangıç tarihi",
+    "GanttDependency": "Dependency",
+    "GanttDependencyFinishToFinish": "Finish to finish",
+    "GanttDependencyFinishToStart": "Finish to start",
+    "GanttDependencyStartToFinish": "Start to finish",
+    "GanttDependencyStartToStart": "Start to start",
+    "GanttLag": "Lag",
     "Manual": "Manuel",
     "All": "Tümü",
     "PastWeek": "Geçen hafta",

plugins/tracker-assets/lang/zh.json

@@ -125,6 +125,13 @@
     "NoAssignee": "无受理人",
     "LastUpdated": "最后更新",
     "DueDate": "截止日期",
+    "IssueStartDate": "开始日期",
+    "GanttDependency": "Dependency",
+    "GanttDependencyFinishToFinish": "Finish to finish",
+    "GanttDependencyFinishToStart": "Finish to start",
+    "GanttDependencyStartToFinish": "Start to finish",
+    "GanttDependencyStartToStart": "Start to start",
+    "GanttLag": "Lag",
     "Manual": "手动",
     "All": "全部",
     "PastWeek": "过去一周",

plugins/tracker-resources/src/components/CreateIssue.svelte

@@ -186,6 +186,7 @@
       priority: priority ?? IssuePriority.NoPriority,
       space: _space as Ref<Project>,
       component: component ?? $activeComponent ?? null,
+      startDate: null,
       dueDate: null,
       attachments: 0,
       estimation: 0,
@@ -312,6 +313,7 @@
         _id: generateId(),
         space: _space as Ref<Project>,
         subIssues: [],
+        startDate: null,
         dueDate: null,
         labels:
           p.labels !== undefined
@@ -488,6 +490,7 @@
         rank: '',
         comments: 0,
         subIssues: 0,
+        startDate: object.startDate,
         dueDate: object.dueDate,
         parents:
           parentIssue != null

plugins/tracker-resources/src/components/SubIssues.svelte

@@ -86,6 +86,7 @@
         rank: '',
         comments: 0,
         subIssues: 0,
+        startDate: subIssue.startDate ?? null,
         dueDate: null,
         parents,
         reportedTime: 0,

plugins/tracker-resources/src/components/milestones/NewMilestone.svelte

@@ -34,6 +34,7 @@
     status: MilestoneStatus.Planned,
     comments: 0,
     attachments: 0,
+    startDate: null,
     targetDate: Date.now() + 14 * 24 * 60 * 60 * 1000
   }
 

plugins/tracker-resources/src/components/templates/DraftIssueChildEditor.svelte

@@ -71,6 +71,7 @@
       assignee: project.defaultAssignee ?? null,
       status: project.defaultIssueStatus,
       space: project._id,
+      startDate: null,
       dueDate: null,
       subIssues: [],
       attachments: 0,

plugins/tracker/src/index.ts

@@ -119,6 +119,22 @@ export enum IssuePriority {
   Low
 }
 
+/**
+ * Dependency kind between two Issues for Gantt scheduling.
+ *
+ * - `finish-to-start` (FS): A must finish before B can start. Most common.
+ * - `start-to-start` (SS): A must start before B can start.
+ * - `finish-to-finish` (FF): A must finish before B can finish.
+ * - `start-to-finish` (SF): A must start before B can finish. Rare.
+ *
+ * @public
+ */
+export type DependencyKind =
+  | 'finish-to-start'
+  | 'start-to-start'
+  | 'finish-to-finish'
+  | 'start-to-finish'
+
 /**
  * @public
  */
@@ -175,6 +191,7 @@ export interface Milestone extends Doc {
   comments: number
   attachments?: number
 
+  startDate: Timestamp | null // null = open-ended begin marker
   targetDate: Timestamp
 }
 
@@ -196,6 +213,8 @@ export interface Issue extends Task {
   relations?: RelatedDocument[]
   parents: IssueParentInfo[]
 
+  startDate: Timestamp | null // for Gantt scheduling; null = unscheduled
+
   space: Ref<Project>
 
   milestone?: Ref<Milestone> | null
@@ -236,6 +255,7 @@ export interface IssueDraft {
   assignee: Ref<Person> | null
   component: Ref<Component> | null
   space: Ref<Project>
+  startDate: Timestamp | null
   dueDate: Timestamp | null
   milestone?: Ref<Milestone> | null
 
@@ -323,6 +343,22 @@ export interface IssueParentInfo {
   space: Ref<Space>
 }
 
+/**
+ * Typed dependency between two Issues, used by the Gantt view to compute
+ * cascade scheduling and critical path.
+ *
+ * Persisted as an AttachedDoc collection 'relations' on the source Issue.
+ *
+ * @public
+ */
+export interface IssueRelation extends AttachedDoc {
+  attachedTo: Ref<Issue>           // source / predecessor
+  target: Ref<Issue>               // successor
+  kind: DependencyKind
+  /** Lag in schedule days; can be negative (overlap). */
+  lag: number
+}
+
 /**
  * @public
  */
@@ -366,6 +402,7 @@ const pluginState = plugin(trackerId, {
   class: {
     Project: '' as Ref<Class<Project>>,
     Issue: '' as Ref<Class<Issue>>,
+    IssueRelation: '' as Ref<Class<IssueRelation>>,
     IssueTemplate: '' as Ref<Class<IssueTemplate>>,
     Component: '' as Ref<Class<Component>>,
     IssueStatus: '' as Ref<Class<IssueStatus>>,
@@ -520,6 +557,13 @@ const pluginState = plugin(trackerId, {
     Project: '' as IntlString,
     RelatedIssues: '' as IntlString,
     Issue: '' as IntlString,
+    IssueStartDate: '' as IntlString,
+    GanttDependency: '' as IntlString,
+    GanttDependencyFinishToFinish: '' as IntlString,
+    GanttDependencyFinishToStart: '' as IntlString,
+    GanttDependencyStartToFinish: '' as IntlString,
+    GanttDependencyStartToStart: '' as IntlString,
+    GanttLag: '' as IntlString,
     NewProject: '' as IntlString,
     UnsetParentIssue: '' as IntlString,
     ForbidCreateProjectPermission: '' as IntlString,

services/github/pod-github/src/sync/issueBase.ts

@@ -69,6 +69,7 @@ WithMarkup<Issue>,
 | 'reports'
 | 'childInfo'
 | 'dueDate'
+| 'startDate'
 | 'kind'
 | 'reviews'
 | 'reviewThreads'

services/github/pod-github/src/sync/issues.ts

@@ -868,6 +868,7 @@ export class IssueSyncManager extends IssueSyncManagerBase implements DocSyncMan
       rank: calcRank(lastOne, undefined),
       comments: 0,
       subIssues: 0,
+      startDate: null,
       dueDate: null,
       parents: [],
       reportedTime: 0,

services/github/pod-github/src/sync/pullrequests.ts

@@ -1169,6 +1169,7 @@ export class PullRequestSyncManager extends IssueSyncManagerBase implements DocS
       rank: calcRank(lastOne, undefined),
       comments: 0,
       subIssues: 0,
+      startDate: null,
       dueDate: null,
       parents: [],
       reportedTime: 0,