feat(stats): link stats rows and counts to filtered lists (#65)

Wire the stats page to filter_url()/stats_links:
- Per-row session links on game superlatives, games-by-playtime, platform
  and month rows (game rows keep their detail GameLink, add a session icon).
- Count links: sessions, games, total/refunded/dropped/unfinished/backlog
  purchases.
- Cap preview lists to 5 with a 'View all (N)' link passing ?sort= for order
  parity; remove the redundant 'All Purchases' list.
- stats_data: carry platform_id for platform links; drop the all-time
  games-by-playtime [:10] slice so the view-all count is honest (rendering
  caps the preview).

Also make the filter bar's _extract_labeled tolerate bare choice/multi values
so a programmatically-built filter URL renders instead of crashing.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01RF5L4HtbcykTfY9YUYGds3

tests/test_filter_bar_labels.py

@@ -0,0 +1,18 @@
+"""The filter bar must render a filter whose choice/multi values are bare
+(no embedded {id, label}) — e.g. a programmatically built filter from
+stats_links — without crashing (#65)."""
+
+from common.components.filters import _extract_labeled
+
+
+def test_extract_labeled_handles_labeled_dicts():
+    assert _extract_labeled([{"id": "game", "label": "Game"}]) == [("game", "Game")]
+
+
+def test_extract_labeled_handles_bare_values():
+    # bare scalars (ids/choices) fall back to using the value as its own label
+    assert _extract_labeled(["game", "dlc"]) == [("game", "game"), ("dlc", "dlc")]
+
+
+def test_extract_labeled_handles_bare_ints():
+    assert _extract_labeled([3, 7]) == [("3", "3"), ("7", "7")]

tests/test_stats_content_links.py

@@ -0,0 +1,115 @@
+"""Rendering tests: stats page wires rows/counts to filtered-list links (#65)."""
+
+from datetime import datetime, timedelta, timezone
+
+import pytest
+from django.utils.html import escape
+
+from games.filters import filter_url
+from games.models import Game, Platform, PlayEvent, Purchase, Session
+from games.views import stats_links
+from games.views.stats_content import stats_content
+from games.views.stats_data import compute_stats
+
+YEAR = 2024
+
+
+def _dt(month, day, hour=12):
+    return datetime(YEAR, month, day, hour, 0, tzinfo=timezone.utc)
+
+
+@pytest.fixture
+def rendered(db):
+    pc = Platform.objects.create(name="PC")
+    # 6 games each played in-year → games-by-playtime exceeds the cap of 5.
+    games = []
+    for index in range(6):
+        game = Game.objects.create(
+            name=f"Game {index}", platform=pc, status=Game.Status.PLAYED
+        )
+        start = _dt(6, index + 1)
+        Session.objects.create(
+            game=game,
+            timestamp_start=start,
+            timestamp_end=start + timedelta(hours=index + 1),
+        )
+        games.append(game)
+
+    abandoned = Game.objects.create(
+        name="Abandoned", platform=pc, status=Game.Status.ABANDONED
+    )
+    Purchase.objects.create(date_purchased=_dt(1, 5), type=Purchase.GAME).games.set(
+        [games[0]]
+    )
+    Purchase.objects.create(date_purchased=_dt(2, 5), type=Purchase.GAME).games.set(
+        [abandoned]
+    )  # dropped
+    Purchase.objects.create(
+        date_purchased=_dt(3, 5), date_refunded=_dt(4, 5), type=Purchase.GAME
+    ).games.set([games[1]])  # refunded
+    Purchase.objects.create(date_purchased=_dt(5, 5), type=Purchase.GAME).games.set(
+        [games[2]]
+    )  # unfinished
+
+    finished_game = games[0]
+    PlayEvent.objects.create(game=finished_game, ended=_dt(8, 1))
+
+    ctx = compute_stats(YEAR)
+    return {"html": str(stats_content(ctx)), "pc": pc, "games": games}
+
+
+def _href(builder_filter, **extra):
+    return escape(filter_url(builder_filter, **extra))
+
+
+def test_total_count_links_to_purchases(rendered):
+    assert _href(stats_links.purchases_total(YEAR)) in rendered["html"]
+
+
+def test_refunded_count_links_to_refunded_purchases(rendered):
+    assert _href(stats_links.purchases_refunded(YEAR)) in rendered["html"]
+
+
+def test_dropped_count_links_to_dropped_purchases(rendered):
+    assert _href(stats_links.purchases_dropped(YEAR)) in rendered["html"]
+
+
+def test_unfinished_count_links_to_unfinished_purchases(rendered):
+    assert _href(stats_links.purchases_unfinished(YEAR)) in rendered["html"]
+
+
+def test_platform_row_links_to_platform_sessions(rendered):
+    url = _href(stats_links.sessions_for_platform(rendered["pc"].id, YEAR))
+    assert url in rendered["html"]
+
+
+def test_game_row_has_session_link(rendered):
+    # at least one games-by-playtime game links to its sessions
+    any_game = rendered["games"][0]
+    url = _href(stats_links.sessions_for_game(any_game.id, YEAR))
+    assert url in rendered["html"]
+
+
+def test_games_by_playtime_capped_with_view_all(rendered):
+    # 6 games played, capped to 5 → a "View all" link to games_played
+    assert "View all" in rendered["html"]
+    view_all = filter_url(stats_links.games_played(YEAR), sort="-playtime")
+    # the filter portion (before &sort) must be present even after attr-escaping
+    assert escape(view_all.split("&")[0]) in rendered["html"]
+
+
+def test_all_purchases_section_removed(rendered):
+    assert "All Purchases" not in rendered["html"]
+
+
+def test_generated_links_resolve_to_200(rendered, client, django_user_model):
+    """A stats link, when visited, returns 200 with its filter applied."""
+    user = django_user_model.objects.create_user(username="u", password="p")
+    client.force_login(user)
+    for builder in (
+        stats_links.purchases_total(YEAR),
+        stats_links.purchases_dropped(YEAR),
+        stats_links.sessions_for_platform(rendered["pc"].id, YEAR),
+    ):
+        response = client.get(filter_url(builder), follow=True)
+        assert response.status_code == 200