Add signed route-decision and runtime evidence stack

[coreytshaffer]

Summary

Adds a broader TriageCore evidence and verification stack spanning CR-082 through CR-093.

This PR includes signed route-decision verification work, reviewer-facing smoke/checkpoint documentation, reviewer entrypoint documentation, runtime efficiency evidence records, controlled runtime experiment planning, experiment trace lineage, and deterministic experiment trace export smoke artifacts.

The runtime-evidence portion establishes the “observable, traceable, data-driven” direction for comparing local model/runtime choices without adding live model calls, autonomous orchestration, runtime migration, payment/token-custody behavior, or measured energy-savings claims.

Included slices

• CR-082: Signed Route Decision Verification Path
• CR-083: Signed Route Decision Smoke Example
• CR-084: Identity Doctor Route-Decision Capability Check
• CR-085: Signed Route Decision Checkpoint
• CR-086: Stabilization Reviewer Checkpoint
• CR-087: Reviewer Smoke Runbook
• CR-088: Submission Video Runbook
• CR-089: Reviewer Entrypoints Index
• CR-090: Runtime Efficiency Ledger
• CR-091: Controlled Runtime Experiment Harness
• CR-092: Experiment Observability Trace Contract
• CR-093: Experiment Trace Export Smoke

Validation

CI passed across the configured pytest matrix:

• pytest (3.10) passed
• pytest (3.11) passed
• pytest (3.12) passed

Focused local validation also passed for the runtime evidence stack, including runtime efficiency, controlled experiment, trace contract, and trace smoke tests.

Boundaries

• No Ollama-to-llama.cpp migration
• No live benchmark execution
• No autonomous orchestration
• No payment/token-custody behavior
• No measured energy-savings claims
• Runtime evidence smoke artifacts use synthetic token_proxy evidence only

Reviewer note

This PR is broader than the runtime evidence stack alone. It completes the signed route-decision reviewer path first, then layers on the runtime evidence and experiment trace contracts needed for observable, traceable, data-driven runtime comparison work.