feat(views): wire derived views onto InformationSpace + integration (WP-0010 T5)

Expose backlinks(name), recent_changes(), all_pages(), site_map() on
InformationSpace. Integration test exercises all four over two shards (BackLinks
aggregate across shards, AllPages/SiteMap span the union, RecentChanges merges an
alias decision with shard edits). SCOPE updated; WP-0010 done. 152 tests green.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

tests/test_views_integration.py

@@ -0,0 +1,52 @@
+"""Integration: derived views exposed on InformationSpace over two shards (SHARD-WP-0010 T5)."""
+
+from shard_wiki.adapters import FolderAdapter
+from shard_wiki.model import Identity
+from shard_wiki.space import InformationSpace
+
+
+def _shard(tmp_path, name, files):
+    root = tmp_path / name
+    for rel, text in files.items():
+        p = root / rel
+        p.parent.mkdir(parents=True, exist_ok=True)
+        p.write_text(text, encoding="utf-8")
+    return FolderAdapter(name, root)
+
+
+def _space(tmp_path):
+    space = InformationSpace("space")
+    space.attach(
+        _shard(tmp_path, "wiki", {"Home.md": "welcome, see [[Guide]]", "Guide.md": "the guide"})
+    )
+    space.attach(_shard(tmp_path, "notes", {"Daily.md": "today I read [[Guide]]"}))
+    return space
+
+
+def test_backlinks_across_two_shards(tmp_path):
+    space = _space(tmp_path)
+    sources = {bl.source for bl in space.backlinks("Guide")}
+    assert sources == {Identity("wiki", "Home"), Identity("notes", "Daily")}
+
+
+def test_all_pages_and_site_map_over_union(tmp_path):
+    space = _space(tmp_path)
+    names = {e.name for e in space.all_pages()}
+    assert names == {"Home", "Guide", "Daily"}
+    leaves = {p.key for p in space.site_map().pages}
+    assert {"Home", "Guide", "Daily"} <= leaves
+
+
+def test_recent_changes_includes_alias_and_edits(tmp_path):
+    space = _space(tmp_path)
+    space.alias("Start", "wiki:Home", actor="ana")
+    feed = space.recent_changes()
+    kinds = {e.kind for e in feed}
+    assert "alias" in kinds and "edit" in kinds
+    alias = next(e for e in feed if e.kind == "alias")
+    assert alias.source == "coordination" and alias.actor == "ana"
+
+
+def test_red_link_creates_no_backlink_via_space(tmp_path):
+    space = _space(tmp_path)
+    assert space.backlinks("Nonexistent") == ()