VSTD 1.2.0: decompose generic-run runtime without semantic drift

[TimeLordRaps]

Coordinate

VSTD 1.2.0 release-candidate maintainability work for the generic-run implementation. Do not combine
this refactor with a wire migration or normative redesign.

Target

Use characterization tests to separate manifest planning, execution capture, receipt
validation, inspection, reproduction, and impact analysis from the oversized generic-run
module while preserving:

• strict profile dispatch;
• canonical digest behavior;
• arbitrary-command and no-sandbox warnings;
• UNKNOWN, conflict, and failure semantics;
• historical layer4_binding reads and current frozen-profile writes;
• zero required runtime dependencies.

Exit criteria

• Existing and new characterization tests pass before and after each extraction.
• Public imports, commands, schemas, receipt bytes, and error semantics remain compatible.
• No shared helper collapses producer/checker independence boundaries.
• Each commit is independently reviewable and behavior preserving.

[TimeLordRaps]

Implemented in stacked pull request #27 at d941df4.

Evidence:

• verifier.core.run remains the compatibility facade and capture/model owner, reduced from 1,823 lines/726 statements to about 941 lines/301 statements.
• Planning, validation, inspection, reproduction, impact analysis, and shared support types now have separate owner modules.
• Historical imports and receipts remain readable; profile, canonical digest, warning, UNKNOWN/conflict/failure, layer4_binding, and zero-runtime-dependency behavior are preserved.
• Implementation hashes now bind the complete seven-module inventory; parser hashes bind the validation owner, so newly emitted mechanism identities reflect the moved bytes truthfully.
• Characterization tests verify facade ownership, mechanism inventory binding, and compatibility. Focused generic-run tests (35) and the full suite (402) passed; hosted Python 3.10-3.13, standard-library, wheel, reproducibility, and conformance jobs all passed in run 33038825743.

The issue remains open for review and will be resolved by landing #27.