feat(routing): persist validated route outcomes

[MCamner]

Why

The routing control room needs durable evidence before any task class can be considered for promotion. Persisting only successful candidates would create survivorship bias and make malformed-output and Ollama-unavailable escalation impossible to audit.

What Changed

• add an idempotent, file-locked writer for mq.model-route-outcome.v1
• validate against mq-agent's authoritative schema instead of copying it
• persist PASS as well as escalated FAIL, SKIPPED, and UNAVAILABLE evidence
• reject raw/unknown fields, sensitive material, contradictory acceptance, and corrupt history
• keep routing/outcomes.jsonl local and gitignored
• document the writer/report handoff and add a sanitized example

Verification

• 65 mqobsidian unit tests pass
• a duplicate write remains one JSONL record
• an actual mq-agent security route is stored as SKIPPED/escalated
• mq-agent route report reads two stored records as one verified and one escalated
• export, sensitive-content, token-budget, and context-link checks pass