Hack Day: CALM Architecture Conformance Gates in CI

## Summary
Introduce CALM/Architecture-as-Code conformance gates for TraderX state generation and evolution.

## Jump-Off State(s)
- `012-platform-convergence-c3`

## Graph Intent
`canonical candidate`

## Scope
- Encode architecture constraints as machine-checkable policies.
- Add CI gates for architecture drift and policy violations.
- Integrate findings with existing SpecKit validation flow.

## Acceptance Criteria
- CI fails on defined architecture policy violations.
- Rule set is versioned and reviewable with state changes.
- Dev guidance exists for remediation workflows.

## Decision Gate (Promote/Park)
Promote if this improves architectural consistency without creating excessive friction.

Start by inspecting the 012-platform-convergence-c3 state and the existing SpecKit validation flow to identify where architecture policies and CI checks belong. Define the versioned rule set and remediation guidance, then verify that CI rejects the specified policy violations without excessive friction.

Written by the indexing model from the issue text.