Adds two orthogonal identity fields to the anonymous telemetry beacon so we
can segment usage by integration surface and deployment shape:
- headroom_stack: how Headroom is invoked (proxy, wrap_claude, wrap_codex,
adapter_ts_openai, adapter_ts_anthropic, etc.). Resolved from HEADROOM_STACK
env, HEADROOM_AGENT_TYPE fallback, or aggregated request-header counts.
- install_mode: how the proxy is deployed (wrapped / persistent / on_demand).
Detected from HEADROOM_AGENT_TYPE plus DeploymentManifest lookup.
TS SDK adapters now tag every request with X-Headroom-Stack; a FastAPI
middleware buckets the counts and surfaces them via /stats so the beacon can
report requests_by_stack for mixed-integration sessions.
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
