Pattern graph v2: explicit typed relations and graph-backed suggestions

[rajanbor]

Outcome

Replace ambiguous legacy relationship data with reviewed typed claims and use graph context to improve explanations.

Inputs

• Pattern Schema v1 relations
• existing legacy related lists
• registry catalog

Outputs

• typed relations in the registry contract
• incoming/outgoing graph queries and stable JSON
• recommendation explanations referencing relevant edges

Constraints

• slash-form IDs remain canonical
• legacy related remains readable throughout schema v1
• do not infer stronger semantics automatically
• every migrated edge requires human review and optional evidence

Acceptance criteria

• Registry builder parses and emits explicit relations
• Shared registry parser validates relation types and targets
• Published patterns migrate in reviewable batches
• Graph supports incoming and outgoing filters with deterministic ordering
• Suggestions state whether graph evidence or a compatibility-normalized edge was used

Depends on #103.