feat: dashboard maps the activity, follows a ticket's way and the proposals

Three more blocks on the project dashboard, also by REST, GraphQL and
MCP:
- Activity: what moved each day of the last 12 weeks, in a heatmap,
  with the busiest weekday and the longest lull.
- A ticket's way: for the tickets done in the last 90 days, where the
  time from created to done went, status by status (waiting included),
  and how much of it was work (flow efficiency).
- The public's proposals: received, waiting, under way, done and
  discarded, and the most voted still unanswered.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

libs/web/tracker/domain/src/lib/models/insights.ts

@@ -126,6 +126,33 @@ export interface FieldBreakdown {
   none: number;
 }
 
+/** Where a closed ticket's time goes, status by status. */
+export interface Journey {
+  /** Tickets done in the last 90 days. */
+  samples: number;
+  leadDays: number | null;
+  /** Part of the lead time at work (an in-progress status), 0–100. */
+  flowEfficiency: number | null;
+  steps: { status: string; days: number; share: number }[];
+}
+
+/** The public's proposals, from received to done or discarded. */
+export interface ProposalsFunnel {
+  received: number;
+  receivedLately: number;
+  waiting: number;
+  underWay: number;
+  done: number;
+  discarded: number;
+  topWaiting: {
+    id: string;
+    key: string;
+    title: string;
+    votes: number;
+    days: number;
+  }[];
+}
+
 /** The dashboard's reading of a project beyond the counts. */
 export interface ProjectInsights {
   generatedAt: string;
@@ -140,6 +167,11 @@ export interface ProjectInsights {
   backlog: BacklogHealth;
   quality: Quality;
   fields: FieldBreakdown[];
+  /** 12 weeks from a Monday, a day each (84). */
+  heatmap: { day: string; count: number }[];
+  journey: Journey;
+  /** Null while nobody has proposed anything. */
+  proposals: ProposalsFunnel | null;
 }
 
 /** One of my active projects at a glance. */