The v5.0.0-rc.1 N5 implementation looked up hotspot.path in
calibrateAgainstApi() but token-hotspots.mjs only emitted hotspot.source —
calibration silently produced 0 actual_tokens because every iteration hit
the `if (!hotspot?.path) continue` guard.
Fix: file-backed hotspots now expose `path: h.absPath` in the JSON output.
MCP-server hotspots intentionally leave path unset — their tokens are
runtime tool-schema (formula-based: 500 + toolCount × 200), not file
content readable by count_tokens.
SC-6b release-gate verified against tests/fixtures/marketplace-large:
- Actual (count_tokens, claude-opus-4-7): 589 tokens for CLAUDE.md
- Estimated (4-bytes/token byte heuristic): 594 tokens
- Delta: -5 tokens / -0.85% — well within ±5% gate. PASS.
CHANGELOG: documented the fix + SC-6b result inline under [5.0.0].
All 635 tests still green. No estimateTokens tuning required for v5.0.0.
Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>