feat: add declarative Profile Runtime v1

[chasechou007]

Summary

• add strict repository-local Integration Profile and Sidecar Domain Declaration schemas
• add deterministic Profile registry, safe file/bundle Source Units, Native Mapping, and Sidecar mapping
• add explicit and automatic Profile selection plus integrations list/validate
• add Profile-aware initialization, ERP examples, documentation, and installed-package smoke coverage

Boundaries

• Grounding Protocol v1 stable fields remain unchanged
• Profiles normalize only explicit structured values; no prose inference or invented OpenDomain IDs
• executable plugins, Embedded Declaration, Candidate promotion, Spec Kit presets, and consumer conformance remain deferred

Validation

• Node.js 20: 107 tests passed
• default OpenDomain validation: 24 documents
• ERP validation: 7 documents
• ERP Profile validation: 1 Profile
• explicit and automatic Profile grounding: 5 accepted sources plus 1 proposed Candidate boundary
• npm audit: 0 vulnerabilities
• package dry-run: 56 entries
• installed tarball smoke: passed