Add fixed-dimension member identity to routine interfaces

[jscott3201]

Summary

• bump the canonical routine interface contract to v3
• require ordered authored member IDs for fixed dimensions while retaining specialization ownership for parameter-driven members
• enforce extent counts and cross-dimension uniqueness with deterministic regression coverage

Scope

This is a canonical input prerequisite for later scalarization and source maps. It does not add a specializer, generated bundle schema, production routine, registry row, CXF artifact, or Engine/Studio behavior.

Validation

• 23 focused routine schema tests
• 105 complete lint tests
• routine schema, semantic, catalog, registry, point, and SVG gates
• G36 source inventory check: 431 release and 693 development files
• Rust verifier tests, routine mode, and all fault scenarios
• dataset harness tests and tiny LBL FPU replay
• book generation and mdBook build
• git diff --check

[jscott3201]

Cycle 1 — PASS at 4f5da6c6802f5309d947d54a3a4fb9b935de7445.

Both independent reviewers are blocker/major-clean. No minor or nit findings were deferred. The interface-v3 ownership split, closed dimension variants, extent/member checks, cross-dimension uniqueness, deterministic diagnostics, documentation, and scope boundaries were verified. Exact-head build and verify checks are green; deploy is correctly skipped.