emit platform meter + traces telemetry on Gemini escalation paths

[haasonsaas]

This is the most-starred MCP in the evalops org (105★ at time of filing). Its core value is model-escalation: Claude Code hands off to Gemini for huge-context sweeps. Today nobody sees the cost side of that escalation — every user pays Anthropic + Google directly with no central visibility.

Ask

Wire two optional platform integrations (env-gated, no behavior change when unset):

1. meter: fire `meter.v1.MeterService/RecordUsage` on every completed Claude call AND every completed Gemini call with:

   • `model` = resolved model id (e.g. `claude-opus-4-7`, `gemini-2.5-pro`)
   • `provider` = "anthropic" or "google"
   • `surface` = "deep-code-reasoning-mcp"
   • `event_type` = "analysis" / "escalation" / "conversation"
   • `input_tokens`, `output_tokens`, `total_cost_usd`, `metadata.escalation_reason`

2. traces: record one trace per analysis request with spans for each Claude ↔ Gemini turn. Emit `AnnotateTraceQuality` with `quality_per_dollar` so the cost-of-escalation is queryable.

Payoff

• First read surface for this MCP's usage — no other repo has visibility into it today
• Feeds `evalops/console#15` attribution panel (per-agent revenue via `agent_id = "deep-code-reasoner"`)
• Token budgets from `evalops/platform#611` (llm-gateway budgets) become enforceable for MCP surfaces
• The structural story "evalops's 105-star wedge produces data flywheel signal" becomes true

Non-goals

• Not required by default — MIT users who never set the env vars see no change
• Not gating the Claude/Gemini calls; purely telemetry

Related

• `evalops/platform/internal/meter/` — the ingest endpoint
• `evalops/platform/internal/traces/` — quality annotation path (recently upgraded by `evalops/platform#609`)
• `meter: emit per-call token-usage events for cost attribution kestrel#14` — same meter pattern, different consumer

Scope

~3-4 days.