Timeline: place dots by co-op stage at the event date

Each date-field event is now plotted on the lane corresponding to the Framework Stage the co-op was in on the field's stored date, resolved from the activity stream's stage transitions. Date_Opened is pinned to Stage 5 as the journey anchor. Events that pre-date any known transition fall back to the field's section rank so they still surface somewhere. Extracts the STAGE_RANK map (previously inline in ReportView) into lib/stageRank.ts alongside the new buildStageRankAtDate resolver factory.

components/report/DateTimeline.tsx

@@ -5,21 +5,29 @@ import { formatShortDate } from "./FieldHistory";
 
 /**
  * Date-grouped timeline strip at the top of the report. Walks every
- * date-type field across stage sections 1–5, pulls each field's
+ * date-type field across all stage sections, pulls each field's
  * most-recent entered date, and plots events into five horizontal swim
  * lanes — one per stage, Stage 5 on top down to Stage 1 at the bottom.
- * Stage 5's `Date_Opened` gets visual emphasis as the journey's anchor
- * at the right end of the time axis. A faint "Today" tick anchors the
- * reader if today falls within the range, and an adaptive month/year
- * axis runs beneath the lanes. Each dot exposes a tooltip on hover or
- * keyboard focus.
+ *
+ * Each dot is placed on the lane corresponding to the stage the co-op
+ * was in on the field's stored date, resolved via `stageRankAtDate`
+ * over the activity stage-transition history. When the date precedes
+ * any known transition (no evidence), we fall back to the field's own
+ * section rank so the dot still appears somewhere sensible. Stage 5's
+ * `Date_Opened` is forced to Stage 5 and gets visual emphasis as the
+ * journey's anchor at the right end of the time axis. A faint "Today"
+ * tick anchors the reader if today falls within the range, and an
+ * adaptive month/year axis runs beneath the lanes. Each dot exposes a
+ * tooltip on hover or keyboard focus.
  */
 export function DateTimeline({
   sections,
   fieldHistory,
+  stageRankAtDate,
 }: {
   sections: StageSectionConfig[];
   fieldHistory: Record<string, FieldHistoryEntry[]>;
+  stageRankAtDate?: (isoDate: string) => number | null;
 }) {
   type Event = {
     rank: number;
@@ -29,18 +37,25 @@ export function DateTimeline({
   };
   const events: Event[] = [];
   for (const section of sections) {
-    if (section.rank < 1 || section.rank > 5) continue;
     for (const f of section.fields) {
       if (f.type !== "date") continue;
       const history = fieldHistory[f.name];
       if (!history || history.length === 0) continue;
       const v = history[0].value;
       if (typeof v !== "string" || v.length === 0) continue;
+      const isOpened = f.name === "Date_Opened";
+      const resolved = stageRankAtDate?.(v) ?? null;
+      // Date_Opened is the Stage-5 anchor by definition. Otherwise prefer
+      // the stage in effect on the event date; fall back to the field's
+      // section rank when no transition history covers that point.
+      let rank = isOpened ? 5 : (resolved ?? section.rank);
+      if (rank < 1 || rank > 5) rank = section.rank;
+      if (rank < 1 || rank > 5) continue;
       events.push({
-        rank: section.rank,
+        rank,
         fieldLabel: f.label,
         date: v,
-        isOpened: f.name === "Date_Opened",
+        isOpened,
       });
     }
   }