chore(release): coordinate integrity and performance source updates

Release v0.1.46. Coordinated integrity review: GovOPlaN/govoplan-core#298.

docs/operations/INTEGRITY_SOURCE_RELEASE_2026_09.md

@@ -0,0 +1,91 @@
+# Integrity and performance source release — September 2026
+
+Coordinated tracking: [Core #298](https://git.add-ideas.de/GovOPlaN/govoplan-core/issues/298).
+This source publication advances only the affected packages; it is not a signed
+catalog publication, runtime-image release, or remote production rollout.
+
+## Package set
+
+| Package | Version |
+| --- | --- |
+| Core / developer meta-package | 0.1.46 |
+| Addresses | 0.1.23 |
+| Calendar | 0.1.24 |
+| Campaign | 0.1.29 |
+| Cases | 0.1.25 |
+| Committee | 0.1.22 |
+| Connectors | 0.1.27 |
+| Dataflow | 0.1.25 |
+| Datasources | 0.1.26 |
+| Files | 0.1.27 |
+| Forms Runtime | 0.1.22 |
+| IDM | 0.1.26 |
+| Mail | 0.1.28 |
+| Reporting | 0.1.22 |
+| Tickets | 0.1.23 |
+
+Consumers of new Core helpers require Core 0.1.46 or later. Dataflow and
+Datasources also require the matching Core WebUI contract. The release manifests,
+immutable Git lock, and developer package describe this coordinated composition.
+Unchanged packages retain their independent versions.
+
+## Database and data integrity
+
+The reviewed additive heads are Connectors `d2a4c6e8f0b1`, Datasources
+`e2b8d4a0f6c3`, Files `a2b3c4d5e701`, and Mail `b5d6e7f8091a`.
+Back up the target deployment and rehearse its normal upgrade before rollout.
+Never downgrade away retained CSV originals without a separate recovery plan.
+Files preserves historical duplicate copies; Mail leaves legacy maildrop identity
+unset rather than guessing an account. A schema upgrade does not authorize POP3
+retrieval/reconciliation, provider deletion, or message resending.
+
+Development startup may automatically apply pending migrations after a watched
+source change. Therefore, inspect actual Alembic heads and schema before assuming
+a live development database is still at its pre-change state. A backup taken
+after such an upgrade is a current-state recovery copy, not a pre-upgrade backup.
+
+On 8 September, the local PostgreSQL development database already contained all
+four heads. Schema and constraint inspection passed; recomputing the Files
+identity backfill checked 7,385 rows with zero mismatches. A private current-state
+database backup was created. Per-instance backup paths and row contents are not
+published in this repository. The implementation's initial receipt claiming no
+live migration occurred was incorrect: watched development-server restarts had
+applied the migration files automatically. Restoring the backup into an isolated
+PostgreSQL 16 cluster and running the normal upgrade preserved all 281 public
+tables, 142,287 rows, and migration heads exactly. Both Datasources PostgreSQL
+concurrency regressions passed. The test-only cluster was then stopped.
+
+Release preparation additionally corrected Alembic's ConfigParser handling of
+percent-escaped connection URLs, preserving the exact database URL. The static
+migration auditor now recognizes the existing reviewed development-wrapper
+aliases and peer filenames without executing migration code; historical
+migrations are unchanged.
+
+## Verification and boundaries
+
+The implementation passed the required focused workspace gate, including 63
+frontend build configurations and 230 browser conformance tests. Owning-module
+regressions cover exact import/rollback evidence, authorization-before-pagination,
+bounded recurrence and response processing, collision-safe attachment naming,
+and stale asynchronous UI completion. English/German feature documentation stays
+in each owning module; Core documents shared integrity contracts.
+
+Mock-provider tests and local work-count measurements do not establish production
+throughput or provider race behavior. Real S3/SMB/Seafile and POP3 acceptance,
+representative load testing, and deployment authentication checks remain separate
+operational validation. Source tags trigger package workflows; a pushed source
+tag alone does not prove a registry artifact or signed catalog is published.
+
+## Deutsch
+
+Dieses koordinierte Quellrelease veröffentlicht nur die betroffenen Pakete.
+Produktions-Images, signierter Modulkatalog und entfernte Produktivinstanzen
+werden dadurch nicht ausgerollt. Die vier Migrationen bewahren bestehende Daten;
+historische POP3-Zuordnungen werden nicht geraten. POP3 ist ein eigener
+Import-Arbeitsablauf innerhalb von **Mail**, kein separat installierbares Modul.
+
+Der Entwicklungsserver kann Migrationen beim automatischen Neustart nach einer
+Quelländerung bereits anwenden. Tatsächliche Schema-Stände prüfen; eine danach
+erstellte Sicherung enthält den aktuellen Stand und ist keine Sicherung vor dem
+Upgrade. Externe Transportaktionen, erneutes Versenden und Löschungen werden
+durch die Migration oder Quellveröffentlichung nicht ausgelöst.

requirements-release.txt

@@ -4,15 +4,15 @@
 govoplan-tenancy @ git+ssh://git@git.add-ideas.de/GovOPlaN/govoplan-tenancy.git@v0.1.22
 govoplan-organizations @ git+ssh://git@git.add-ideas.de/GovOPlaN/govoplan-organizations.git@v0.1.21
 govoplan-identity @ git+ssh://git@git.add-ideas.de/GovOPlaN/govoplan-identity.git@v0.1.21
-govoplan-idm @ git+ssh://git@git.add-ideas.de/GovOPlaN/govoplan-idm.git@v0.1.25
+govoplan-idm @ git+ssh://git@git.add-ideas.de/GovOPlaN/govoplan-idm.git@v0.1.26
 govoplan-access @ git+ssh://git@git.add-ideas.de/GovOPlaN/govoplan-access.git@v0.1.25
 govoplan-admin @ git+ssh://git@git.add-ideas.de/GovOPlaN/govoplan-admin.git@v0.1.23
 govoplan-policy @ git+ssh://git@git.add-ideas.de/GovOPlaN/govoplan-policy.git@v0.1.23
 govoplan-audit @ git+ssh://git@git.add-ideas.de/GovOPlaN/govoplan-audit.git@v0.1.20
 govoplan-dashboard @ git+ssh://git@git.add-ideas.de/GovOPlaN/govoplan-dashboard.git@v0.1.20
-govoplan-files @ git+ssh://git@git.add-ideas.de/GovOPlaN/govoplan-files.git@v0.1.26
+govoplan-files @ git+ssh://git@git.add-ideas.de/GovOPlaN/govoplan-files.git@v0.1.27
-govoplan-mail @ git+ssh://git@git.add-ideas.de/GovOPlaN/govoplan-mail.git@v0.1.27
+govoplan-mail @ git+ssh://git@git.add-ideas.de/GovOPlaN/govoplan-mail.git@v0.1.28
-govoplan-campaign @ git+ssh://git@git.add-ideas.de/GovOPlaN/govoplan-campaign.git@v0.1.28
+govoplan-campaign @ git+ssh://git@git.add-ideas.de/GovOPlaN/govoplan-campaign.git@v0.1.29
-govoplan-calendar @ git+ssh://git@git.add-ideas.de/GovOPlaN/govoplan-calendar.git@v0.1.23
+govoplan-calendar @ git+ssh://git@git.add-ideas.de/GovOPlaN/govoplan-calendar.git@v0.1.24
 govoplan-docs @ git+ssh://git@git.add-ideas.de/GovOPlaN/govoplan-docs.git@v0.1.23
 govoplan-ops @ git+ssh://git@git.add-ideas.de/GovOPlaN/govoplan-ops.git@v0.1.22

tests/test_release_migration_audit.py

@@ -65,6 +65,8 @@ branch_labels: Union[str, Sequence[str], None] = None
             )
             wrapper = development / release.name
             wrapper.write_text(
+                "from importlib import import_module\n"
+                '_migration = import_module("govoplan_core.backend.migrations.versions.1234_example")\n'
                 "revision = _migration.revision\n"
                 "down_revision = _migration.down_revision\n"
                 "depends_on = _migration.depends_on\n"
@@ -79,6 +81,150 @@ branch_labels: Union[str, Sequence[str], None] = None
         self.assertEqual(("base",), migration.down_revisions)
         self.assertEqual(("core",), migration.depends_on)
 
+    def test_literal_wrapper_alias_and_different_filename_are_resolved_without_execution(self) -> None:
+        audit = load_audit_module()
+        with tempfile.TemporaryDirectory(prefix="migration-audit-test-") as directory:
+            root = Path(directory)
+            (root / "versions").mkdir()
+            (root / "dev_versions").mkdir()
+            (root / "versions/1234_v019_example.py").write_text(
+                'revision = "1234"\ndown_revision = "base"\ndepends_on = "core"\nbranch_labels = None\n'
+                'raise AssertionError("Migration implementation must not execute")\n',
+                encoding="utf-8",
+            )
+            wrapper = root / "dev_versions/1234_example.py"
+            for alias in ("_migration", "edit_revision", "message_actions"):
+                with self.subTest(alias=alias):
+                    wrapper.write_text(
+                        "from importlib import import_module as load_migration\n"
+                        f'{alias} = load_migration("govoplan_campaign.backend.migrations.versions." "1234_v019_example")\n'
+                        f"revision = {alias}.revision\ndown_revision = {alias}.down_revision\n"
+                        f"depends_on = {alias}.depends_on\nbranch_labels = {alias}.branch_labels\n"
+                        'raise AssertionError("Wrapper must not execute")\n',
+                        encoding="utf-8",
+                    )
+                    migration = audit.parse_migration_file("govoplan-campaign", wrapper)
+                    self.assertEqual(migration.revision, "1234")
+                    self.assertEqual(migration.down_revisions, ("base",))
+                    self.assertEqual(migration.depends_on, ("core",))
+
+    def test_core_literal_sibling_file_wrapper_is_resolved_without_execution(self) -> None:
+        audit = load_audit_module()
+        with tempfile.TemporaryDirectory(prefix="migration-audit-test-") as directory:
+            root = Path(directory)
+            (root / "versions").mkdir()
+            (root / "dev_versions").mkdir()
+            (root / "versions/1234_example.py").write_text(
+                'revision = "1234"\ndown_revision = None\ndepends_on = None\nbranch_labels = None\n'
+                'raise AssertionError("Migration implementation must not execute")\n',
+                encoding="utf-8",
+            )
+            wrapper = root / "dev_versions/1234_example.py"
+            wrapper.write_text(
+                "from importlib.util import module_from_spec, spec_from_file_location\n"
+                "from pathlib import Path\n"
+                '_path = Path(__file__).resolve().parents[1] / "versions" / "1234_example.py"\n'
+                '_spec = spec_from_file_location("synthetic_migration", _path)\n'
+                "_module = module_from_spec(_spec)\n_spec.loader.exec_module(_module)\n"
+                "revision = _module.revision\ndown_revision = _module.down_revision\n"
+                "depends_on = _module.depends_on\nbranch_labels = _module.branch_labels\n",
+                encoding="utf-8",
+            )
+            migration = audit.parse_migration_file("govoplan-core", wrapper)
+            self.assertEqual(migration.revision, "1234")
+            self.assertEqual(migration.down_revisions, ())
+
+    def test_wrapper_rejects_dynamic_foreign_missing_or_rebound_targets(self) -> None:
+        audit = load_audit_module()
+        with tempfile.TemporaryDirectory(prefix="migration-audit-test-") as directory:
+            root = Path(directory)
+            (root / "versions").mkdir()
+            (root / "dev_versions").mkdir()
+            (root / "versions/1234_example.py").write_text('revision = "1234"\n', encoding="utf-8")
+            wrapper = root / "dev_versions/1234_example.py"
+            valid = '_migration = import_module("govoplan_campaign.backend.migrations.versions.1234_example")\n'
+            definitions = (
+                '_migration = import_module(module_name)\n',
+                '_migration = import_module("govoplan_mail.backend.migrations.versions.1234_example")\n',
+                '_migration = import_module("govoplan_campaign.backend.migrations.versions...other.1234_example")\n',
+                '_migration = import_module("govoplan_campaign.backend.migrations.versions.missing")\n',
+                valid + "_migration = another_module\n",
+                "import_module = another_loader\n" + valid,
+                "def import_module(value):\n    return another_module\n" + valid,
+                "import another_loader as import_module\n" + valid,
+                valid + "class _migration:\n    revision = 'another'\n",
+                "if condition:\n    _migration = another_module\n" + valid,
+                valid + "del _migration\n",
+            )
+            for definition in definitions:
+                with self.subTest(definition=definition):
+                    wrapper.write_text(
+                        "from importlib import import_module\n" + definition + "revision = _migration.revision\n",
+                        encoding="utf-8",
+                    )
+                    with self.assertRaisesRegex(ValueError, "unsupported or ambiguous"):
+                        audit.parse_migration_file("govoplan-campaign", wrapper)
+
+    def test_wrapper_rejects_symlink_and_mixed_release_metadata(self) -> None:
+        audit = load_audit_module()
+        with tempfile.TemporaryDirectory(prefix="migration-audit-test-") as directory:
+            root = Path(directory)
+            (root / "versions").mkdir()
+            (root / "dev_versions").mkdir()
+            (root / "versions/1234_example.py").write_text('revision = "1234"\ndown_revision = None\n', encoding="utf-8")
+            (root / "versions/5678_example.py").write_text('revision = "5678"\ndown_revision = None\n', encoding="utf-8")
+            (root / "versions/linked.py").symlink_to(root / "versions/1234_example.py")
+            wrapper = root / "dev_versions/1234_example.py"
+            definitions = (
+                '_migration = import_module("govoplan_campaign.backend.migrations.versions.linked")\nrevision = _migration.revision\n',
+                '_migration = import_module("govoplan_campaign.backend.migrations.versions.1234_example")\n'
+                '_other = import_module("govoplan_campaign.backend.migrations.versions.5678_example")\n'
+                'revision = _migration.revision\ndown_revision = _other.down_revision\n',
+            )
+            for definition in definitions:
+                with self.subTest(definition=definition):
+                    wrapper.write_text("from importlib import import_module\n" + definition, encoding="utf-8")
+                    with self.assertRaisesRegex(ValueError, "unsupported or ambiguous"):
+                        audit.parse_migration_file("govoplan-campaign", wrapper)
+
+    def test_unresolved_revision_expression_is_not_silently_omitted(self) -> None:
+        audit = load_audit_module()
+        with tempfile.TemporaryDirectory(prefix="migration-audit-test-") as directory:
+            path = Path(directory) / "1234_example.py"
+            path.write_text("revision = calculate_revision()\n", encoding="utf-8")
+            with self.assertRaisesRegex(ValueError, "Unsupported or ambiguous migration metadata"):
+                audit.parse_migration_file("govoplan-core", path)
+
+    def test_explicit_metadata_reexport_is_resolved_without_execution(self) -> None:
+        audit = load_audit_module()
+        with tempfile.TemporaryDirectory(prefix="migration-audit-test-") as directory:
+            root = Path(directory)
+            (root / "versions").mkdir()
+            (root / "dev_versions").mkdir()
+            (root / "versions/a234_example.py").write_text(
+                'revision = "1234"\ndown_revision = "base"\ndepends_on = None\nbranch_labels = None\n'
+                'raise AssertionError("Migration implementation must not execute")\n',
+                encoding="utf-8",
+            )
+            wrapper = root / "dev_versions/1234_example.py"
+            source = "govoplan_organizations.backend.migrations.versions.a234_example"
+            wrapper.write_text(f"from {source} import revision, down_revision, depends_on, branch_labels\n", encoding="utf-8")
+            migration = audit.parse_migration_file("govoplan-organizations", wrapper)
+            self.assertEqual(migration.revision, "1234")
+            self.assertEqual(migration.down_revisions, ("base",))
+            for declaration in (
+                f"from {source} import *\n",
+                f"from {source} import revision as down_revision\n",
+                f"from {source} import revision\nrevision = 'different'\n",
+                f"from {source} import revision\nimport another as revision\n",
+                f"from {source} import revision\ndef revision():\n    pass\n",
+                f"from {source.replace('govoplan_organizations', 'govoplan_mail')} import revision\n",
+            ):
+                with self.subTest(declaration=declaration):
+                    wrapper.write_text(declaration, encoding="utf-8")
+                    with self.assertRaises(ValueError):
+                        audit.parse_migration_file("govoplan-organizations", wrapper)
+
     def test_release_baseline_matches_current_heads_in_strict_report(self) -> None:
         audit = load_audit_module()
         migrations = [

tools/inventory/endpoint-surface-declarations.json

@@ -2287,6 +2287,27 @@
       "path": "/tasks/{}",
       "rationale": "Task command clients retrieve one explicit task and its strong revision token; the Work UI already receives the same projection through the aggregated list.",
       "repository": "govoplan-tasks"
+    },
+    {
+      "category": "intentionally_headless",
+      "method": "GET",
+      "path": "/connectors/tabular-sources/{}/original-csv",
+      "rationale": "Authorized connector clients explicitly export retained original CSV after tenant, lifecycle, read-scope and source-integrity checks; ordinary catalogue responses never include source text.",
+      "repository": "govoplan-connectors"
+    },
+    {
+      "category": "intentionally_headless",
+      "method": "GET",
+      "path": "/datasources/{}/materializations/{}/original-csv",
+      "rationale": "Administrators explicitly export retained original CSV through an audited API; current and historical field, row and access policies must permit the entire original and source-integrity checks must pass.",
+      "repository": "govoplan-datasources"
+    },
+    {
+      "category": "intentionally_headless",
+      "method": "POST",
+      "path": "/mail/profiles/{}/pop3/imports/{}/bind-maildrop",
+      "rationale": "Authorized mail operators explicitly reconcile a legacy POP3 import to the current maildrop using confirmed binding, a current transport revision token and an exact retained/downloaded-byte match; the audited API never guesses historical account identity.",
+      "repository": "govoplan-mail"
     }
   ],
   "schema_version": 1

tools/release/release-migration-audit.py

@@ -8,7 +8,7 @@ from datetime import datetime, timezone
 import json
 import os
 from pathlib import Path
-from typing import Any
+from typing import Any, NoReturn
 
 
 META_ROOT = Path(__file__).resolve().parents[2]
@@ -168,12 +168,13 @@ def owner_for_versions_dir(versions_dir: Path) -> str:
 
 
 def parse_migration_file(owner: str, path: Path) -> Migration | None:
+    if path.stat().st_size > 2 * 1024 * 1024:
+        raise ValueError(f"{path}: migration source exceeds the 2 MiB audit bound")
     tree = ast.parse(path.read_text(encoding="utf-8"), filename=str(path))
-    values: dict[str, Any] = {}
+    values = _imported_release_metadata(owner, path, tree)
-    wrapped: Migration | None = None
+    wrapped = _wrapped_release_metadata(owner, path, tree)
-    release_peer = path.parent.parent / "versions" / path.name
+    if values and wrapped:
-    if path.parent.name == "dev_versions" and release_peer.is_file():
+        raise ValueError(f"{path}: mixed migration metadata wrapper styles are ambiguous")
-        wrapped = parse_migration_file(owner, release_peer)
     for statement in tree.body:
         if isinstance(statement, ast.Assign):
             for target in statement.targets:
@@ -196,6 +197,8 @@ def parse_migration_file(owner: str, path: Path) -> Migration | None:
             )
     revision = values.get("revision")
     if not isinstance(revision, str):
+        if "revision" in values:
+            raise ValueError(f"{path}: migration revision must be an explicit string")
         return None
     return Migration(
         owner=owner,
@@ -207,28 +210,200 @@ def parse_migration_file(owner: str, path: Path) -> Migration | None:
     )
 
 
+def _ast_binding_count(tree: ast.Module, name: str) -> int:
+    count = 0
+    for node in ast.walk(tree):
+        if isinstance(node, ast.Name) and node.id == name and isinstance(node.ctx, (ast.Store, ast.Del)):
+            count += 1
+        elif isinstance(node, (ast.FunctionDef, ast.AsyncFunctionDef, ast.ClassDef)) and node.name == name:
+            count += 1
+        elif isinstance(node, (ast.Import, ast.ImportFrom)):
+            count += sum(
+                (alias.asname or (alias.name.split(".")[0] if isinstance(node, ast.Import) else alias.name)) == name
+                for alias in node.names
+            )
+    return count
+
+
+def _release_wrapper_peer(owner: str, path: Path, filename: str) -> Migration:
+    versions = path.parent.parent / "versions"
+    peer = versions / filename
+    if (
+        path.parent.name != "dev_versions"
+        or Path(filename).name != filename or not filename.endswith(".py")
+        or versions.is_symlink() or peer.is_symlink() or not peer.is_file()
+        or peer.resolve().parent != versions.resolve()
+        or peer.stat().st_size > 2 * 1024 * 1024
+    ):
+        raise ValueError(f"{path}: unsupported or ambiguous development migration wrapper")
+    migration = parse_migration_file(owner, peer)
+    if migration is None:
+        raise ValueError(f"{path}: release wrapper target has no migration metadata")
+    return migration
+
+
+def _imported_release_metadata(owner: str, path: Path, tree: ast.Module) -> dict[str, Any]:
+    """Recognize explicit metadata re-exports, never star/dynamic imports."""
+    names = {"revision", "down_revision", "depends_on", "branch_labels"}
+    prefix = f"{owner.replace('-', '_')}.backend.migrations.versions."
+    values: dict[str, Any] = {}
+    targets: set[str] = set()
+    for statement in tree.body:
+        if not isinstance(statement, ast.ImportFrom):
+            continue
+        selected = [alias for alias in statement.names if alias.name in names or (alias.asname or alias.name) in names]
+        if not selected:
+            if (statement.module or "").startswith(prefix) and any(alias.name == "*" for alias in statement.names):
+                raise ValueError(f"{path}: unsupported wildcard migration metadata")
+            continue
+        stem = (statement.module or "").removeprefix(prefix)
+        if (
+            statement.level or not (statement.module or "").startswith(prefix)
+            or not stem or any(character not in "abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789_" for character in stem)
+        ):
+            raise ValueError(f"{path}: unsupported or ambiguous imported migration metadata")
+        targets.add(stem)
+        if len(targets) != 1:
+            raise ValueError(f"{path}: ambiguous imported migration metadata sources")
+        migration = _release_wrapper_peer(owner, path, stem + ".py")
+        projection = {
+            "revision": migration.revision, "down_revision": migration.down_revisions,
+            "depends_on": migration.depends_on, "branch_labels": migration.branch_labels,
+        }
+        for alias in selected:
+            name = alias.asname or alias.name
+            if name != alias.name or name in values or _ast_binding_count(tree, name) != 1:
+                raise ValueError(f"{path}: ambiguous imported migration metadata assignment")
+            values[name] = projection[name]
+    return values
+
+
+def _wrapped_release_metadata(owner: str, path: Path, tree: ast.Module) -> dict[str, Migration]:
+    """Resolve only known literal sibling wrappers, without importing any code."""
+    metadata_names = {"revision", "down_revision", "depends_on", "branch_labels"}
+    aliases: set[str] = set()
+    bindings: dict[str, list[ast.expr]] = {}
+    imported: dict[str, list[str]] = {}
+    for statement in tree.body:
+        if isinstance(statement, ast.ImportFrom) and not statement.level:
+            for alias in statement.names:
+                imported.setdefault(alias.asname or alias.name, []).append(f"{statement.module}.{alias.name}")
+        targets: list[ast.expr] = []
+        value: ast.expr | None = None
+        if isinstance(statement, ast.Assign):
+            targets, value = statement.targets, statement.value
+        elif isinstance(statement, ast.AnnAssign) and statement.value is not None:
+            targets, value = [statement.target], statement.value
+        for target in targets:
+            if isinstance(target, ast.Name) and value is not None:
+                bindings.setdefault(target.id, []).append(value)
+                if target.id in metadata_names and isinstance(value, ast.Attribute) and isinstance(value.value, ast.Name):
+                    aliases.add(value.value.id)
+    if not aliases:
+        return {}
+    if path.parent.name != "dev_versions":
+        raise ValueError(f"{path}: non-literal release migration metadata is unsupported")
+
+    def reject() -> NoReturn:
+        raise ValueError(f"{path}: unsupported or ambiguous development migration wrapper")
+
+    def binding_count(name: str) -> int:
+        return _ast_binding_count(tree, name)
+
+    def assigned(name: str) -> ast.expr:
+        values = bindings.get(name, ())
+        if len(values) != 1 or binding_count(name) != 1 or name in imported:
+            reject()
+        return values[0]
+
+    def imported_as(node: ast.expr, qualified: str) -> bool:
+        return (
+            isinstance(node, ast.Name)
+            and imported.get(node.id) == [qualified]
+            and binding_count(node.id) == 1
+        )
+
+    def call(node: ast.expr, qualified: str, arguments: int) -> bool:
+        return isinstance(node, ast.Call) and imported_as(node.func, qualified) and len(node.args) == arguments and not node.keywords
+
+    def file_wrapper_target(node: ast.expr) -> str:
+        if binding_count("__file__"):
+            reject()
+        if isinstance(node, ast.Name):
+            node = assigned(node.id)
+        if not (
+            isinstance(node, ast.BinOp) and isinstance(node.op, ast.Div)
+            and isinstance(node.right, ast.Constant) and isinstance(node.right.value, str)
+            and isinstance(node.left, ast.BinOp) and isinstance(node.left.op, ast.Div)
+            and isinstance(node.left.right, ast.Constant) and node.left.right.value == "versions"
+        ):
+            reject()
+        root = node.left.left
+        for name in imported:
+            if imported_as(ast.Name(id=name), "pathlib.Path"):
+                expected = ast.parse(f"{name}(__file__).resolve().parents[1]", mode="eval").body
+                if ast.dump(root) == ast.dump(expected):
+                    return node.right.value
+        reject()
+
+    result: dict[str, Migration] = {}
+    resolved: set[Path] = set()
+    for alias in sorted(aliases):
+        value = assigned(alias)
+        if call(value, "importlib.import_module", 1):
+            argument = value.args[0]
+            if not isinstance(argument, ast.Constant) or not isinstance(argument.value, str):
+                reject()
+            prefix = f"{owner.replace('-', '_')}.backend.migrations.versions."
+            if not argument.value.startswith(prefix):
+                reject()
+            stem = argument.value.removeprefix(prefix)
+            if not stem or any(character not in "abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789_" for character in stem):
+                reject()
+            filename = stem + ".py"
+        elif call(value, "importlib.util.module_from_spec", 1):
+            argument = value.args[0]
+            if not isinstance(argument, ast.Name):
+                reject()
+            specification = assigned(argument.id)
+            if not call(specification, "importlib.util.spec_from_file_location", 2):
+                reject()
+            if not isinstance(specification.args[0], ast.Constant) or not isinstance(specification.args[0].value, str):
+                reject()
+            filename = file_wrapper_target(specification.args[1])
+        else:
+            reject()
+        migration = _release_wrapper_peer(owner, path, filename)
+        peer = migration.path
+        resolved.add(peer.resolve())
+        if len(resolved) > 1:
+            reject()
+        result[alias] = migration
+    return result
+
+
 def _migration_assignment_value(
     name: str,
     value: ast.expr,
     *,
-    wrapped: Migration | None,
+    wrapped: dict[str, Migration],
 ) -> Any:
     try:
         return ast.literal_eval(value)
     except (ValueError, TypeError):
         if (
-            wrapped is None
+            not isinstance(value, ast.Attribute)
-            or not isinstance(value, ast.Attribute)
             or not isinstance(value.value, ast.Name)
-            or value.value.id != "_migration"
+            or value.value.id not in wrapped
             or value.attr != name
         ):
-            return None
+            raise ValueError(f"Unsupported or ambiguous migration metadata: {name}")
+    migration = wrapped[value.value.id]
     return {
-        "revision": wrapped.revision,
+        "revision": migration.revision,
-        "down_revision": wrapped.down_revisions,
+        "down_revision": migration.down_revisions,
-        "depends_on": wrapped.depends_on,
+        "depends_on": migration.depends_on,
-        "branch_labels": wrapped.branch_labels,
+        "branch_labels": migration.branch_labels,
     }[name]