Clears false positives on valid .mcp.json (gap matrix, Batch 1):
- ${CLAUDE_PROJECT_DIR} is auto-injected at runtime (CC 2.1.139) and never
needs an env block — now allowlisted.
- POSIX expansions like ${VAR%pattern} / ${VAR:-default} are resolved by
Claude Code (CC 2.1.142); the env-var regex now matches only bare
${IDENTIFIER}, so operator expressions are skipped.
Genuine bare unreferenced vars are still flagged (broken-project regression
intact). The MCP `trust` field is untouched — it is verify-first (point 4),
not part of Batch 1.
Tests: hermetic runtime temp-fixture; 23/23 MCP green, both directions covered.
Ref: docs/cc-2.1.x-gap-matrix.md
Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01Ter3E2JSi1Khgmuf2kady8