feat: admit Chongqing real-source metadata baseline

[zhouning]

Summary

• add a path-free, content-addressed Chongqing real-source admission manifest and validator
• record 11 source groups, 16 asset profiles, 57 governance blockers, and 584 extracted-file metadata entries
• gate the evidence in CI and staging release test parity
• move AR-2 to in_progress while preserving the System-of-Record authority boundary
• supersede historical stacked PR feat: admit Chongqing real-source metadata baseline #53 with a mainline-scoped slice

Authority boundary

This PR is metadata-only. It does not commit source payloads, absolute paths, row values, geometry, or credentials. It does not authorize source content admission, immutable Landing authority, ResourceVersion or Run creation, scheduler submission, provider mutation, production ingestion, or production readiness.

Verification

• 18 focused tests passed
• 26 CI validators passed
• 693 required platform tests passed
• 5 PostgreSQL contract tests passed against a fresh temporary PostgreSQL 16 database
• git diff --check passed