fix(bundler): bundle update uninstalls components dropped by new version (#3353)

On refresh (bundle update), install_bundle iterated only the new plan's
components, so a component the previous version owned but the new one no
longer ships was left installed on disk while being dropped from the
rewritten record (contributed only holds plan.components). With no
record referencing it, remove_bundle could never clean it up —
permanently orphaned, violating the provenance invariant (FR-022). After
the component loop, when refresh and a prior record exists, uninstall
each previously-owned component absent from the new plan — unless another
bundle still needs it (components_still_needed refcount, mirroring
remove_bundle), in which case it stays installed and is simply
de-attributed. Runs inside the existing try so a failed removal takes the
same no-record-written rollback path.

Co-authored-by: Claude Fable 5 <noreply@anthropic.com>

tests/integration/test_bundler_install_flow.py

@@ -220,3 +220,68 @@ def test_pre_existing_component_is_not_attributed_or_removed(tmp_path: Path):
 
     remove_bundle(tmp_path, "demo-bundle", installer)
     assert ("extensions", "ext-a") in installer.installed
+
+
+def _bundle(manifest_id, ext_ids, *, version="1.0.0"):
+    data = valid_manifest_dict()
+    data["bundle"]["id"] = manifest_id
+    data["bundle"]["version"] = version
+    data["provides"] = {
+        "extensions": [{"id": e, "version": version} for e in ext_ids]
+    }
+    return BundleManifest.from_dict(data)
+
+
+def test_update_uninstalls_components_dropped_by_new_version(tmp_path: Path):
+    """`bundle update` must uninstall components the new version no longer
+    ships, instead of orphaning them (installed on disk, tracked by nothing)."""
+    make_project(tmp_path)
+    installer = FakeInstaller()
+
+    man_v1 = _bundle("demo", ["ext-a", "ext-b"])
+    install_bundle(tmp_path, _plan(man_v1), installer, manifest=man_v1)
+    assert ("extensions", "ext-b") in installer.installed
+
+    man_v2 = _bundle("demo", ["ext-a"], version="2.0.0")
+    result = install_bundle(
+        tmp_path, _plan(man_v2), installer, manifest=man_v2, refresh=True
+    )
+
+    # ext-b was dropped by v2 -> uninstalled and reported.
+    assert ("extensions", "ext-b") in installer.remove_calls
+    assert ("extensions", "ext-b") in {(c.kind, c.id) for c in result.uninstalled}
+    assert ("extensions", "ext-b") not in installer.installed
+    assert ("extensions", "ext-a") in installer.installed
+
+    # The saved record lists only ext-a.
+    rec = next(r for r in load_records(tmp_path) if r.bundle_id == "demo")
+    keys = {(c.kind, c.id) for c in rec.contributed_components}
+    assert ("extensions", "ext-a") in keys
+    assert ("extensions", "ext-b") not in keys
+
+
+def test_update_keeps_component_still_needed_by_sibling_bundle(tmp_path: Path):
+    """A dropped component still owned by another bundle stays installed."""
+    make_project(tmp_path)
+    installer = FakeInstaller()
+
+    man_sib = _bundle("sibling", ["ext-b"])
+    install_bundle(tmp_path, _plan(man_sib), installer, manifest=man_sib)
+
+    man_v1 = _bundle("demo", ["ext-a", "ext-b"])
+    install_bundle(tmp_path, _plan(man_v1), installer, manifest=man_v1)
+
+    man_v2 = _bundle("demo", ["ext-a"], version="2.0.0")
+    install_bundle(
+        tmp_path, _plan(man_v2), installer, manifest=man_v2, refresh=True
+    )
+
+    # ext-b is still needed by 'sibling' -> not removed, stays installed.
+    assert ("extensions", "ext-b") not in installer.remove_calls
+    assert ("extensions", "ext-b") in installer.installed
+
+    # But demo's record no longer attributes it.
+    rec = next(r for r in load_records(tmp_path) if r.bundle_id == "demo")
+    assert ("extensions", "ext-b") not in {
+        (c.kind, c.id) for c in rec.contributed_components
+    }