[sjkim1127]

[AUTOMATED]

Scope

Add a standalone bounded MSF 7 stream reader for future PDB work. It exposes the PDB information stream's GUID, age, signature and version, without connecting the reader to the evaluator or changing any score, cache or existing backend. The limits and unsupported formats are documented.

This is a small building block for the native Windows work discussed in #36; API naming and future integration should be coordinated with maintainers. It does not require #91. Reading an identity does not establish that a PDB belongs to a PE: a future integration must compare the PE's CodeView GUID and age. It does not parse PDB types, symbols or function ranges.

Validation

• Four focused tests passed, including a clang-cl/lld-link cross-compiled fixture compared with llvm-pdbutil.
• A Windows Snappy PDB from qualification-v2 at the frozen revision agrees with llvm-pdbutil on stream count and information-stream identity.
• Ruff, Black and mypy passed for the new Python files. A related test set has the same two failures on the pinned base and this branch (32 passed / 2 failed on base; 36 passed / 2 failed with the new tests). Full suite, PE pairing, native Windows execution and end-to-end scoring have not been validated.