4c1ab5c27e
Adds tools/api_audit.py, a read-only static audit of the public API surface, and docs/api-audit.md, its first run against this revision. The audit answers three questions the reference cannot answer about itself: 1. Does every declared export exist, have a docstring, and appear in docs/api.md? It reads the root __all__ plus each submodule's __all__. 2. How complete is each public definition? Docstring presence, detected docstring convention, parameter and return annotations. 3. Which public names do examples and tests actually use but the reference never explains? That set is the real documentation gap. It parses with ast and never imports the package, so it costs no numpy/cv2 import and cannot be affected by the environment. Findings on this revision (full detail in docs/api-audit.md): - 393 public classes/methods/functions; 65% have a docstring, 32% have a fully annotated signature, 38 document their return value. - 243 docstrings are unstructured prose, 137 are absent, 13 use Google or NumPy sections. There is effectively one convention: none. - 9 of the 18 root exports are absent from docs/api.md, including StreamPipeline, StreamRecorder, mosaic_videos and FFCFrameProcessor - the pipelined multi-stream and offline-recording paths. - Six sub-surfaces have zero coverage in the reference: unroll (18 exports), capture (17), hhd + solvers (7), pipeline (3), export (2). - 74 names are used by examples or tests but absent from the reference. - 21 public classes are exported nowhere; LowpassFilter is documented in docs/api.md and importable, but declared in no __all__. No behaviour change: a new tool and a new document, no source file touched.