opentakeoff-mcp 0.9.20

What's Changed

• docs: 0.9.19 released bullet — the record follows the verified publish by @QuisutDeus1 in #174
• server: lock /ai behind an X-API-Key gate (fail-closed) by @QuisutDeus1 in #175
• Estimator approval seals — human-only ink, agent marks stay pencil by @QuisutDeus1 in #176
• symbol_sweep: every instance of a repeated symbol from one example; dimension annotation — mcp 0.9.20 by @QuisutDeus1 in #177

Full Changelog: mcp-v0.9.19...mcp-v0.9.20