Tracker /v1/route now resolves HF model nodes (by hf_repo or short name)
in addition to preset models, using the same greedy interval-cover logic.
This allows distributed inference routing across two nodes each holding
half the model.
Endpoint dedup: re-registering the same endpoint atomically replaces the
old entry so stale registrations don't accumulate across node restarts.
Purge logging: tracker now prints when a node expires due to missed
heartbeats so operators can see dead nodes being removed.
Timing fix: heartbeat timeout raised from 30s to 90s (3 missed beats);
node heartbeat interval lowered from 30s to 20s to maintain margin.
Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>