… http + unix)

Parameterize ci/run-integration.sh by a TRANSPORT env (subprocess|http|unix)
and run the SAME test/sql/*.test suite over each, in CI as a
transport × os matrix (3 transports × {ubuntu, macos}).

The in-process mock provider server (tests/mock_server.py) is started ONCE,
out of band (via `python -m tests.mock_server`, which now prints URL:<base>
and blocks), and its VGI_SCHOLAR_*_BASE_URL vars are exported so the worker
reads them over every transport — stdio, HTTP, or AF_UNIX. For http/unix the
script boots the worker itself (cwd = repo) and discovers the endpoint:
http via `--http --port 0 --port-file <f>` (poll the file), unix via
`--unix <sock>` (poll for the socket). A single cleanup() (capturing $? first)
kills both the mock server and the worker.

http leg specifics (resolved, not gated):
- inject `INSTALL httpfs FROM core; LOAD httpfs;` after each `LOAD vgi;`
  (the vgi HTTP transport runs on DuckDB's httpfs);
- the http extra (waitress): add `http = ["vgi-python[http]>=0.8.3"]` to
  pyproject and bump scholar_worker.py's PEP 723 dep to vgi-python[http];
  CI syncs `--extra http`.
- SILENT-SKIP GUARD: fail the leg unless the runner reports
  `All tests passed (N>0 assertions)` and zero skips (the runner auto-SKIPs
  any "HTTP"/"Unable to connect" error → a fake green).

scholar_search paging already works over HTTP unchanged: its per-scan cursor
is externalized in _ScanState(ArrowSerializableDataclass), which the framework
round-trips through its continuation token across ticks/requests. No worker fix
was needed.

Status: subprocess=GREEN (33 assertions), unix=GREEN (33), http=GREEN
(35 = 33 + the injected httpfs INSTALL/LOAD).

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>