fix(evidence): distinguish implicit corpus ownership

.superpowers/sdd/evidence-task-5c-report.md

@@ -135,3 +135,10 @@ run reached unrelated Task 6 immutable-file tamper tests; those files were delib
   manifest, and that mismatched job, GC, and search paths perform no vector/filesystem mutations.
 
 Focused workspace-binding, search-pack, preprocess JSON, and scoped Ruff/diff tests pass.
+
+Compatibility follow-up: direct/internal `CorpusPipeline` instances now distinguish an omitted
+workspace identity from an explicit config/job identity. An unbound instance adopts the persisted
+ACTIVE owner (or `default` only for a brand-new direct corpus), preserving safe resume/GC tests and
+the real pgvector lifecycle. Explicit config/job identities still fail closed on any mismatch. The
+two reported regressions, workspace mismatch guards, real Docker lifecycle, scoped Ruff/diff, and
+the full harness suite all pass.

harness/tht/corpus/pipeline.py

@@ -70,7 +70,7 @@ class CorpusPipeline:
         self, *, store: CorpusStore, sources: list[EvidenceSource], embedder,
         vector_store: VectorStore, embedding_model: str, embedding_dimensions: int,
         chunk_policy: ChunkPolicy, pipeline_version: str, retain_published_generations: int = 3,
-        workspace_id: str = "default",
+        workspace_id: str | None = None,
     ) -> None:
         self.store = store
         self.sources = sources
@@ -88,8 +88,13 @@ class CorpusPipeline:
     def _assert_workspace_binding(self) -> None:
         manifest = self.store.active_manifest()
         if manifest is None:
+            if self.workspace_id is None:
+                self.workspace_id = "default"
             return
         persisted = manifest.metadata.get("workspace_id")
+        if self.workspace_id is None and isinstance(persisted, str):
+            self.workspace_id = persisted
+            return
         if persisted != self.workspace_id:
             raise PipelineError(
                 "corpus belongs to a different workspace; use a new corpus root or explicit rebuild"