feat(schema): add cards.assignee and subtask date fields

Three new optional fields, idempotent ensure helpers:

- cards.assignee: free-text label rendered above the card bar
  on the new /plan Gantt. Empty by default.
- subtasks.start_date: ISO date or empty. Lets subtasks appear
  on the Gantt under their parent card with their own duration.
- subtasks.target_date: same, for the bar end.

Live migration confirmed idempotent — first run added the
fields, second run reported both already present.

scripts/setup-remote.ts

@@ -360,6 +360,31 @@ async function ensureCardNarrativeFields(pb: PocketBase): Promise<void> {
   }
 }
 
+async function ensureSubtaskDateFields(pb: PocketBase): Promise<void> {
+  const subtasks = await pb.collections.getOne("subtasks");
+  const have = new Set(subtasks.fields.map((f: { name: string }) => f.name));
+
+  const fields = [...(subtasks.fields as unknown[])];
+  let changed = false;
+
+  for (const field of [
+    { name: "start_date", type: "date", required: false },
+    { name: "target_date", type: "date", required: false },
+  ]) {
+    if (!have.has(field.name)) {
+      fields.push({ ...field, presentable: false, hidden: false, system: false });
+      changed = true;
+    }
+  }
+
+  if (changed) {
+    await pb.collections.update(subtasks.id, { fields });
+    console.log("  + subtasks fields: start_date, target_date");
+  } else {
+    console.log("  = subtasks date fields already present");
+  }
+}
+
 async function ensureCardNumbers(pb: PocketBase): Promise<void> {
   const cards = await pb.collections.getOne("cards");
   const have = new Set(cards.fields.map((f: { name: string }) => f.name));
@@ -505,6 +530,29 @@ async function ensureCardProposalFields(pb: PocketBase): Promise<void> {
   }
 }
 
+async function ensureCardAssigneeField(pb: PocketBase): Promise<void> {
+  const cards = await pb.collections.getOne("cards");
+  const have = new Set(cards.fields.map((f: { name: string }) => f.name));
+
+  if (have.has("assignee")) {
+    console.log("  = cards.assignee already present");
+    return;
+  }
+
+  const fields = [...(cards.fields as unknown[])];
+  fields.push({
+    name: "assignee",
+    type: "text",
+    required: false,
+    max: 120,
+    presentable: false,
+    hidden: false,
+    system: false,
+  });
+  await pb.collections.update(cards.id, { fields });
+  console.log("  + cards field: assignee");
+}
+
 /**
  * Extend the activity `action` select with Plan Puzzle v1's three new values:
  * `column_changed`, `date_proposed`, `date_proposal_resolved`. Existing rows
@@ -1525,6 +1573,11 @@ async function main(): Promise<void> {
   // Add the Plan Puzzle v1 proposal fields and the partial index.
   await ensureCardProposalFields(pb);
 
+  // Add the Gantt plan redesign's optional assignee text and the subtask
+  // date fields (Phase 10).
+  await ensureCardAssigneeField(pb);
+  await ensureSubtaskDateFields(pb);
+
   // Extend activity.action with the three new puzzle actions.
   await ensureActivityActionValues(pb);
 

src/lib/pb/types.ts

@@ -114,6 +114,8 @@ export interface CardRecord extends BaseRecord {
   proposed_target_date?: string;
   proposed_by?: string;
   proposed_at?: string;
+  /** Free-text label rendered above the card bar on the Gantt. Optional. */
+  assignee: string;
 }
 
 export interface SubtaskRecord extends BaseRecord {
@@ -121,6 +123,10 @@ export interface SubtaskRecord extends BaseRecord {
   title: string;
   done: boolean;
   position: number;
+  /** ISO date string, or "" when unset. Mirrors cards.start_date. */
+  start_date: string;
+  /** ISO date string, or "" when unset. Mirrors cards.target_date. */
+  target_date: string;
 }
 
 export interface CommentRecord extends BaseRecord {