fix(discovery): read the session stats and duration the API actually sends

CHANGELOG.md

@@ -11,6 +11,21 @@ follows [Semantic Versioning](https://semver.org/).
 
 _Feature module implementation (iam, billing, workspace, discovery) in progress._
 
+### Fixed (Session history stats and duration — `bugfix/discovery-history-stats-contract`)
+
+- **The session history now shows its stats columns and the duration of live sessions.** The session
+  model expected `storiesGeneratedCount`, `storiesAcceptedCount`, `pendingSuggestionsCount` and
+  `questionsCount`, but the API sends `storiesGenerated`, `storiesAccepted`, `suggestionsPending` and
+  `questionsAsked`. As a result:
+  - the Historias / Aceptadas / Pendientes / Preguntas columns never appeared;
+  - the session separator in Captura never showed its story count.
+
+  The duration cell only read `audioDurationMs`, which live sessions never set, so every live session
+  showed "—".
+- The model now uses the API names and adds `durationSeconds`. The duration cell prefers it and still
+  falls back to `audioDurationMs` for older deployments. The logic lives in the new pure helpers
+  `sessionDuration` and `hasSessionStats` (`history.helpers.ts`), which have unit tests.
+
 ### Added
 
 - **MVP feature flags** (`feature/mvp-feature-flags`): a typed `features` map in both environment

src/app/features/discovery/data/discovery.models.ts

@@ -15,12 +15,21 @@ export interface DiscoverySessionResponse {
   processingError: string | null;
   createdAt: string;
   updatedAt: string;
-  // Per-session stats being added by a parallel backend branch — absent on older
-  // deployments, so every consumer must degrade gracefully when undefined.
-  storiesGeneratedCount?: number | null;
-  storiesAcceptedCount?: number | null;
-  pendingSuggestionsCount?: number | null;
-  questionsCount?: number | null;
+  /**
+   * Recording length in seconds: the audio length of an uploaded recording, otherwise start to stop of
+   * a live session; null while a live session is still running.
+   */
+  durationSeconds?: number | null;
+  // Per-session stats, only on the get/list endpoints (null on lifecycle responses such as start/stop),
+  // so every consumer must degrade gracefully when null or undefined.
+  /** Backlog stories whose source is this session. */
+  storiesGenerated?: number | null;
+  /** Story suggestions of this session the analyst accepted (questions excluded). */
+  storiesAccepted?: number | null;
+  /** Suggestions of this session still pending review. */
+  suggestionsPending?: number | null;
+  /** Clarifying questions the AI raised in this session. */
+  questionsAsked?: number | null;
 }
 
 /** Raw transcript of a session (GET /sessions/{id}/transcript; large text kept off the session resource). */

src/app/features/discovery/pages/discovery-chat/discovery-chat.ts

@@ -330,13 +330,13 @@ import { HlmButton, HlmIcon, HlmSpinner } from '../../../../shared/ui';
                           {{ sessionAt | date: 'MMM d · HH:mm' }}
                         }
                         @if (
-                          block.session.storiesGeneratedCount !== null &&
-                          block.session.storiesGeneratedCount !== undefined
+                          block.session.storiesGenerated !== null &&
+                          block.session.storiesGenerated !== undefined
                         ) {
                           ·
                           {{
                             'discovery.sessionStories'
-                              | transloco: { count: block.session.storiesGeneratedCount }
+                              | transloco: { count: block.session.storiesGenerated }
                           }}
                         }
                       </span>

src/app/features/discovery/pages/history/history.helpers.spec.ts

@@ -0,0 +1,30 @@
+import { describe, expect, it } from 'vitest';
+import { hasSessionStats, sessionDuration } from './history.helpers';
+
+describe('sessionDuration', () => {
+  it('formats the API durationSeconds of a live session', () => {
+    expect(sessionDuration({ durationSeconds: 117, audioDurationMs: 0 })).toBe('1:57');
+  });
+
+  it('prefers durationSeconds over audioDurationMs', () => {
+    expect(sessionDuration({ durationSeconds: 138, audioDurationMs: 138_175 })).toBe('2:18');
+  });
+
+  it('falls back to the uploaded audio length when durationSeconds is absent', () => {
+    expect(sessionDuration({ audioDurationMs: 95_412 })).toBe('1:35');
+  });
+
+  it('shows a dash for a running live session', () => {
+    expect(sessionDuration({ durationSeconds: null, audioDurationMs: 0 })).toBe('—');
+  });
+});
+
+describe('hasSessionStats', () => {
+  it('is true when a session carries storiesGenerated, even zero', () => {
+    expect(hasSessionStats([{ storiesGenerated: null }, { storiesGenerated: 0 }])).toBe(true);
+  });
+
+  it('is false when no session carries stats', () => {
+    expect(hasSessionStats([{}, { storiesGenerated: null }])).toBe(false);
+  });
+});

src/app/features/discovery/pages/history/history.helpers.ts

@@ -0,0 +1,22 @@
+import { formatElapsed } from '../../components/session-bar/session-bar';
+import { DiscoverySessionResponse } from '../../data/discovery.models';
+
+/**
+ * Duration cell of the history table: the API's `durationSeconds` (audio length of an upload, start to
+ * stop of a live session), else the uploaded audio length for older deployments, else a dash.
+ */
+export function sessionDuration(
+  session: Pick<DiscoverySessionResponse, 'durationSeconds' | 'audioDurationMs'>,
+): string {
+  if (session.durationSeconds !== null && session.durationSeconds !== undefined) {
+    return formatElapsed(session.durationSeconds * 1000);
+  }
+  return session.audioDurationMs > 0 ? formatElapsed(session.audioDurationMs) : '—';
+}
+
+/** True when at least one session carries the per-session stats, so the stats columns are shown. */
+export function hasSessionStats(
+  sessions: readonly Pick<DiscoverySessionResponse, 'storiesGenerated'>[],
+): boolean {
+  return sessions.some((s) => s.storiesGenerated !== null && s.storiesGenerated !== undefined);
+}

src/app/features/discovery/pages/history/history.ts

@@ -1,12 +1,20 @@
-import { ChangeDetectionStrategy, Component, OnInit, computed, inject, input, signal } from '@angular/core';
+import {
+  ChangeDetectionStrategy,
+  Component,
+  OnInit,
+  computed,
+  inject,
+  input,
+  signal,
+} from '@angular/core';
 import { DatePipe } from '@angular/common';
 import { Router, RouterLink } from '@angular/router';
 import { TranslocoPipe } from '@jsverse/transloco';
 import { provideIcons } from '@ng-icons/core';
 import { lucideArrowLeft } from '@ng-icons/lucide';
 import { DiscoveryApiService } from '../../data/discovery-api.service';
 import { DiscoverySessionResponse } from '../../data/discovery.models';
-import { formatElapsed } from '../../components/session-bar/session-bar';
+import { hasSessionStats, sessionDuration } from './history.helpers';
 import { HlmButton, HlmIcon, HlmSpinner } from '../../../../shared/ui';
 
 /**
@@ -71,7 +79,9 @@ import { HlmButton, HlmIcon, HlmSpinner } from '../../../../shared/ui';
                       <th class="px-4 py-2.5">{{ 'discovery.history.colStories' | transloco }}</th>
                       <th class="px-4 py-2.5">{{ 'discovery.history.colAccepted' | transloco }}</th>
                       <th class="px-4 py-2.5">{{ 'discovery.history.colPending' | transloco }}</th>
-                      <th class="px-4 py-2.5">{{ 'discovery.history.colQuestions' | transloco }}</th>
+                      <th class="px-4 py-2.5">
+                        {{ 'discovery.history.colQuestions' | transloco }}
+                      </th>
                     }
                   </tr>
                 </thead>
@@ -98,15 +108,15 @@ import { HlmButton, HlmIcon, HlmSpinner } from '../../../../shared/ui';
                       </td>
                       @if (showStats()) {
                         <td class="px-4 py-3 tabular-nums">
-                          {{ session.storiesGeneratedCount ?? '—' }}
+                          {{ session.storiesGenerated ?? '—' }}
                         </td>
                         <td class="px-4 py-3 tabular-nums">
-                          {{ session.storiesAcceptedCount ?? '—' }}
+                          {{ session.storiesAccepted ?? '—' }}
                         </td>
                         <td class="px-4 py-3 tabular-nums">
-                          {{ session.pendingSuggestionsCount ?? '—' }}
+                          {{ session.suggestionsPending ?? '—' }}
                         </td>
-                        <td class="px-4 py-3 tabular-nums">{{ session.questionsCount ?? '—' }}</td>
+                        <td class="px-4 py-3 tabular-nums">{{ session.questionsAsked ?? '—' }}</td>
                       }
                     </tr>
                   }
@@ -151,9 +161,7 @@ export class DiscoveryHistory implements OnInit {
   private nextPage = 0;
 
   /** Show stats columns only when at least one session actually carries them. */
-  protected readonly showStats = computed(() =>
-    this.sessions().some((s) => s.storiesGeneratedCount !== null && s.storiesGeneratedCount !== undefined),
-  );
+  protected readonly showStats = computed(() => hasSessionStats(this.sessions()));
 
   ngOnInit(): void {
     this.load(0);
@@ -191,7 +199,7 @@ export class DiscoveryHistory implements OnInit {
   }
 
   protected duration(session: DiscoverySessionResponse): string {
-    return session.audioDurationMs > 0 ? formatElapsed(session.audioDurationMs) : '—';
+    return sessionDuration(session);
   }
 
   protected statusClass(status: string): string {