TAS-145: Semantic-window revision process and compatibility delta reports

[AtlantisPleb]

Summary

Public Tassadar needs semantic-window revision process and compatibility delta reports so the executor lane can widen honestly without collapsing profile boundaries, portability, or refusal posture.

Roadmap position

• Tranche: Tranche L | Semantic-window evolution and universality-governance pre-closeout
• Strategic phase: Phase 9/10 governance bridge
• Tranche goal: Govern semantic drift without losing honesty before the terminal contract.
• Why this tranche exists: This tranche exists so widening can continue without silent semantic or claim drift.
• Dependency context: Starts Tranche L after the earlier tranches establish the minimum prerequisites.

Problem

A frozen semantic window is useful, but the roadmap still lacks a principled way to revise that window without creating silent semantic drift.

Hypothesis

Explicit semantic-window revisions plus delta reports will let the system evolve while keeping every widening step challengeable and reproducible.

Public source anchors

• docs/TASSADAR_WASM_RUNBOOK.md
• docs/ROADMAP_TASSADAR.md
• docs/ARCHITECTURE.md

Target surfaces

• docs/
• psionic-eval
• psionic-provider
• psionic-runtime

Claim class

• conformance discipline / promotion discipline

Initial scope

• implement the smallest honest subsystem changes across docs/, psionic-eval, psionic-provider, psionic-runtime that close the named gap
• add deterministic fixtures, receipts, reports, or capability rows that make the new posture machine-legible
• update public docs and capability language only where the new bounded surface is actually supported
• keep unsupported shapes on explicit typed refusal paths rather than widening implicitly

Validation and benchmark expectations

• revision-schema checks
• compatibility-delta reports
• unsupported-window refusal tests
• and operator drills for moving between declared windows
• add negative coverage for unsupported or out-of-profile behavior
• update any machine-readable receipt, report, capability row, or acceptance artifact touched by this lane

Claim-discipline requirements

• keep the capability bounded to named profiles or declared semantic windows
• do not let this issue imply arbitrary Wasm, broad internal compute, or broader served posture unless an explicit promotion gate is part of the task
• preserve explicit refusal reasons for unsupported module shapes, effects, portability envelopes, or semantic families
• treat post-core proposal families, concurrency, and accelerator semantics as separate claim classes rather than inherited core-Wasm support

Done when

• the named surfaces land with deterministic tests, fixtures, or reports that exercise the new bounded capability
• public docs reflect the new capability, limit, or refusal posture in bounded language
• the claim remains benchmarked or promoted only at the level explicitly supported by the landed evidence

Status

• seeded