Attach BDD specs to CALM nodes/relationships for behavioural conformance

## Feature Proposal

### Target Project:
To be decided - can be a calm-bdd at root or under an appropriate subproject like calm-al or calm-hub

### Description of Feature:
A tool that generates BDD Specs via an AI-driven chat interface and attaches them to CALM elements like a node or relationship or service.
CALM validates structural correctness today, this feature focuses on behavioural correctness. Attaching a BDD spec will given a component business and behavioural intent, bridging the gap between architectural intent to verifiable behaviour.

### User Stories:
As a developer, I want to see the behaviour specs tied to the components I am building so that I know what each piece is expected to do before I implement it.

As an architect, I want to attach a BDD spec to a CALM node, relationship or Service so that the architecture carries explicit testable acceptance criteria alongside the structure

### Current Limitations:
There is no well defined manner to tag BDD to calm components today.

### Proposed Implementation:
Technical design: Attach a BDD spec to a CALM element (node, relationship, or service), most likely as a decorator or via the existing controls mechanism.
Dependencies: Builds on the decorators work and the existing controls/standards plumbing, verification would sit alongside calm validate perhaps.