[thekevinbot]

Part of #1042.

Moves the launcher's argv config-path scan out of packages/python/dirsql/cli/resolve_config_extensions.py into its own module, clearing that file's one-function-per-file violation at max_lines = 12 (Kevin's chosen target for the campaign).

_config_paths_from_argv becomes config_paths_from_argv in packages/python/dirsql/cli/config_paths_from_argv.py; with_resolved_extensions stays in the module named for it and imports the scan relatively. The underscore drops because the symbol is now imported across modules; it stays out of every barrel, so nothing about the public API changes.

Mirrors #1039. That PR made exactly this call on the TypeScript twin — moved configPathsFromArgv into packages/ts/src/cli/config-paths-from-argv.ts and kept withResolvedExtensions where it was. Same shape here, so the two launchers keep matching. PR C is doing the remaining TypeScript splits concurrently.

No testing-conventions.toml touched. This is a pure refactor; a separate PR sets the ceilings once every split has landed.

packages/python/dirsql/resolve_config_extensions.py (the non-cli one) violates only at max_lines = 10, so it is out of scope at 12 and untouched.

Verification

testing-conventions@0.0.111 pinned by hand (the workflows call the reusable workflow at @v0 and pin no npm version), against a copy of packages/python/testing-conventions.toml with max_lines = 12:

Before:

packages/python/dirsql/cli/resolve_config_extensions.py:49: one-function-per-file — `with_resolved_extensions` runs 18 lines, and `_config_paths_from_argv` already holds this file; move it to its own module
error: 1 function(s) sharing a file with another function over the 12-line threshold

After: no output — zero violations.

just preflight: 0 failing pair(s), 3 skipped (the three packaging pairs, which need a built artifact). Python unit mutation: no surviving mutants — every mutation was caught (47 mutant(s) tested). Python unit coverage: clean at the 100% floor.

Tests

Behaviour-preserving refactor, so red/green does not apply — there is no new behaviour to fail a test first. The existing cases were split by which unit they actually exercise:

• The 13 argv-parsing cases relocate (not duplicate) out of resolve_config_extensions_test.py into a colocated config_paths_from_argv_test.py that calls the function directly.
• resolve_config_extensions_test.py keeps the launcher's own plumbing — the init and native-config guards, --extension flag construction — and now mocks the scan as a collaborator (mock.patch.object(..., autospec=True)), alongside the resolver it already mocked, satisfying unit lint isolation.

Manual exercise

Built the binary (cargo build -p dirsql --features cli) and the extension module (uv run maturin develop), staged the repo's testext cdylib fixture as an installed package manualext, and ran the CLI path that resolves a config extension by package name:

$ cat .dirsql.toml
[[dirsql.extension]]
path = "manualext"

$ PYTHONPATH=/tmp/.../pkgs dirsql query "SELECT dirsql_testext_answer() AS answer" -c ./.dirsql.toml --format json
[{"answer":42}]

The 42 proves the whole chain through the moved code: the launcher scanned -c ./.dirsql.toml out of argv with config_paths_from_argv, the shared resolver turned manualext into the loadable's literal path, the launcher appended --extension, and the binary loaded it.

E2E Verification

• Ran e2e suites locally for every affected SDK
• Python SDK e2e: pass (37 passed)
• TypeScript SDK e2e: N/A - no TypeScript change
• Rust core e2e (if applicable): N/A - no Rust change
• packages/python/e2e-attestations/<branch>.json receipt written if packages/python changed (just e2e-attest-python)
• packages/ts/e2e-attestations/<branch>.json receipt written if packages/ts changed (just e2e-attest-ts) — not required, packages/ts untouched
• Command(s) run: just test-e2e, then just e2e-attest-python
• Result summary: 37 passed in 13.57s; receipt at packages/python/e2e-attestations/claude-tackle-1042-py12.json (exit 0).

Per #1041, testing-conventions e2e attest (local CLI 0.0.85) pruned 14 unrelated receipts and auto-committed the deletions. The attest commit was rewritten to add the one new receipt and nothing else; git show --stat on it reads 1 file changed, 7 insertions(+).

Changelog / Migrations

• Changelog fragment added under <root>/<pkg>/changelog.d/ for each changed package (or: skip-changelog trailer on a commit with reason) — packages/python/changelog.d/2026-09-04-config-paths-from-argv-module.md
• Migration fragment added under <root>/<pkg>/migrations.d/ (or: not required -- additive/bugfix only)

Migration: not required. The moved symbol was module-private (_config_paths_from_argv), is exported from no barrel, and appears in no documented surface. with_resolved_extensions keeps its name and module, and its only call site (dirsql/cli/main.py) is unchanged. No public API breaks, no deprecation is removed, and runtime behaviour is identical — the manual exercise and the 37-case e2e suite both confirm it.

PARITY.md: no change. Neither config_paths_from_argv nor with_resolved_extensions appears in PARITY.md, packages/python/dirsql/__init__.py, or packages/ts/src/index.ts. No drift introduced, none restored.