Emit translation unit declarations and macros

[MoSafi2]

Summary

• Emit top-level declarations and source-backed macros from the parsed translation unit instead of filtering to configured header paths.
• Remove parser-side embedded-record materialization and primary-header compatibility aliases now that translation-unit cursors are lowered directly.
• Rename the orphan-record reachability repair to signature-only record stub materialization, keeping it only for record refs without standalone top-level cursors.
• Align macro folding with emission: source-backed object-like macros participate in expansion, while compiler/predefined no-file macros are skipped.

Why

The parser now walks the whole translation unit, so several frontend and analysis paths that compensated for primary-header-only parsing were no longer the right abstraction. This makes the parser policy explicit and removes redundant recovery logic while preserving a narrow fallback for signature-only opaque record refs.

Validation

• pixi run precommit
• Commit hook reran the same validation suite: 244 passed, 8 skipped, 15 deselected