feat(model): let the project say what it ships, and rank that first

contributor-scan 2.10. Every one of libpng's twenty-five entry-point
regions was a `main()` -- twenty-three under contrib/, plus example.c and
pngtest.c -- and those regions carried the fifty interprocedural taint
requests that dominated a 300s query phase. A library has no entry points,
so entry-point-driven analysis had nothing to anchor to except its own
example programs.

The task said to derive this rather than hardcode `contrib/`, and a project
already declares it. Makefile.am names installed targets in
`lib_LTLIBRARIES` and `bin_PROGRAMS`, each target's `<target>_SOURCES`
names its files, and `check_PROGRAMS`/`noinst_PROGRAMS` are automake's own
word for "not installed" -- exactly the distinction wanted. Taking every
`_SOURCES` would have called libpng's whole test suite shipped code, since
contrib/libtests declares its sources the same way the library does.

  interprocedural regions   25 -> 1
  taint query               300.1s -> 125.0s
  total query               311.9s -> 138.5s
  regions                   121 -> 121, unchanged by design

The surviving interprocedural region is contrib/tools/pngfix.c:main, which
libpng genuinely installs.

Two rules keep it honest. **Silence is not exclusion**: a project with no
build file this can read gets None back and nothing changes, so vampi's
numbers are untouched. **Not shipped is not unscanned**: those regions are
still arbitrated function-locally, because a contributor editing a test
must still get an answer -- what they lose is the expensive treatment and
first claim on the budget.

Entailed findings went 0 -> 3, and all three are false positives at
contrib/gregbook/wpng.c:374, `strcpy(outname+len, ".png")`. It is safe:
outname is char[256] and line 325 guards with
`if ((len = strlen(inname)) > 250)`. They were not introduced so much as
uncovered -- a different callDepth meant a different sink set, and the 26
fgets false positives were masking them.

The structural cause is recorded as 2.12: c/injection and c/memory carry
ZERO sanitizers, so no C flow can ever be discharged and every
`argv -> strcpy` entails however carefully it is bounded. The discharge
here is not a call but a guard that dominates the sink, which is precisely
what dominance.sc already does for access control and is wired to that one
family.

Also adds Group 7, five tasks for stopping the same false positive twice.
Two of today's three false-positive classes were one bug in three
matchers -- `resolve` in `resolveUrl`, `user` in `users`, `gets` in
`fgets` -- each fixed locally and each next one surviving because nobody
carried the fix across. A model may group counter-examples by cause and
draft an edit; only a split-respecting measurement may adopt one, because
the predecessor's improve lever admitted shapes taught by the holdout pairs
they then recovered and turned a -0.059 Youden into +0.059.

Gates byte-identical.

Co-Authored-By: Claude Opus 5 (1M context) <[email protected]>
Claude-Session: https://claude.ai/code/session_01T7XD7x5KonMdmGRkp63EQG

tests/test_model_regions.py

@@ -210,3 +210,31 @@ def test_a_module_body_is_not_offered_the_handler_families() -> None:
     assert "access_control" not in module.families
     assert "config_secrets" in module.families, "settings are exactly what module bodies carry"
     assert module.source == "module_scope"
+
+
+def test_a_project_that_declares_nothing_is_not_penalised() -> None:
+    """contributor-scan 2.10: silence is not exclusion.
+
+    `declared_sources` returns None for a repository with no build files this can read, and every region
+    stays shipped. A tool that quietly deprioritised code because it could not parse a Makefile would be
+    worse than one that ignores the question.
+    """
+    from openultrasast.model.regions import regions_for
+
+    regions = regions_for([_entry()], [_target()], shipped=None)
+
+    assert all(region.shipped for region in regions)
+
+
+def test_what_the_project_does_not_ship_ranks_below_what_it_does() -> None:
+    """libpng's twenty-five entry points were all `main()` in example programs and test tools."""
+    from openultrasast.model.regions import regions_for
+
+    entries = [_entry(path="lib.py", function="handler", access="public"), _entry(path="example.py", function="main", access="public")]
+    targets = [_target(path="lib.py"), _target(path="example.py")]
+
+    regions = regions_for(entries, targets, shipped=frozenset({"lib.py"}))
+
+    ordered = [(r.path, r.shipped) for r in regions]
+    assert ordered[0] == ("lib.py", True), "shipped code comes first whatever the rank says"
+    assert ("example.py", False) in ordered, "not shipped is not unscanned"