Semantic contract parity and bounded UI shell runtime behavior

[justinrayshort]

Summary

Replace brittle substring-based contract parity checks with typed semantic parity tests and harden shell runtime retention and submission semantics with bounded sequenced session events and typed busy rejection.

Primary Architectural Plane

testing / ui / platform sdk / docs

Owning Subsystem

testing helpers, service-boundary tests, workflows/quant_strategy_promotion tests, ui/crates/system_shell, ui/crates/apps/terminal, ui/crates/desktop_runtime, platform/sdk/sdk-rs, contributor docs

Architectural References

• ARCHITECTURE.md
• DEVELOPMENT_MODEL.md
• docs/architecture/layer-boundaries.md

Integration Boundaries

Allowed touchpoints: contract tests, shell runtime contracts, terminal app persistence, platform SDK local-harness transport, documentation.
Explicit non-goals: broad redesign of desktop runtime storage payload typing.

Scope In

• Add shared typed parity helpers for service-boundary TOML and workflow fixtures
• Replace substring assertions with semantic parsing in touched tests
• Add typed shell submit rejection and bounded sequenced session retention
• Bound SDK local-harness event retention
• Add reducer and integration tests for rejection, cancellation, eviction, and restore semantics
• Document new invariants in contributor and development docs

Scope Out

• Core service repository extraction beyond touched seams
• Additional schema redesign unrelated to parity or shell runtime behavior

Acceptance Criteria

• Touched contract parity tests are semantic, not substring-based
• Shell submit returns typed acceptance or rejection instead of synthetic event IDs
• Session event retention is bounded and sequence-safe for consumers
• Documentation records workspace governance, async boundary, typed ID, contract parity, and simulation separation invariants
• Full repository validation remains green

Validation Requirements

• cargo fmt --all --check
• cargo clippy --workspace --all-targets --all-features -- -D warnings
• cargo test --workspace --all-targets
• cargo xtask architecture audit-boundaries
• cargo xtask plugin validate-manifests
• cargo xtask github audit-process