Task 12 Report — Remove unreachable pgvector runtime code

Status: completed

Summary:

Proved the retired pgvector runtime had no remaining operational adapter call sites after migration by re-running the required grep; only the packaging assertion still mentions migrations/vector.
Removed the obsolete pgvector/HTTP/direct vector runtime modules, vector SQL migrations, and their affected runtime tests.
Kept the operational semantic path on Qdrant and migrated the remaining runtime callers to that path.
Kept psycopg2-binary because DWH direct PostgreSQL and session PostgreSQL code still depend on it.

Implementation notes:

Extracted shared collection/kind validation into harness/tht/adapters/vector/_shared.py so QdrantVectorStore no longer depends on the deleted pgvector module.
Simplified build_vector_store() to return only QdrantVectorStore.
Migrated vector/evidence/memory CLI paths away from legacy pgvector loaders and REST vector clients.
Updated packaging coverage so the built wheel asserts session SQL migrations are present and vector SQL migrations are absent.

Verification:

cd harness && .venv/bin/pytest tests/test_qdrant_vector_store.py tests/test_vector_port_contract.py tests/test_semantic_kind_isolation.py tests/test_vector_migration_packaging.py -q
cd harness && .venv/bin/pytest tests/test_adapter_factory.py tests/test_solved_search_cli.py -q
cd harness && .venv/bin/python -c "import tht.cli, tht.adapters.factory, tht.adapters.vector, tht.vectorstore.reader"
cd harness && uv build
harness/.venv/bin/ruff check harness/tests/test_adapter_factory.py harness/tests/test_solved_search_cli.py harness/tests/test_vector_migration_packaging.py harness/tests/test_vector_port_contract.py harness/tht/adapters/factory.py harness/tht/adapters/vector/__init__.py harness/tht/adapters/vector/_shared.py harness/tht/adapters/vector/qdrant.py harness/tht/cli/evidence_cmd.py harness/tht/cli/memory_cmd.py harness/tht/cli/search_cmd.py harness/tht/cli/vector_cmd.py harness/tht/solved.py harness/tht/vectorstore/reader.py
git diff --check

Notes / concerns:

Repository-wide harness/.venv/bin/ruff check . still reports many pre-existing findings outside this task’s touched files; it is not clean on this branch baseline.
Some legacy config compatibility parsing still exists outside the deleted runtime path. This task removed the unreachable runtime/migration code without broad config-schema refactoring.