chore: remove stale 2026-02-14 deploy session summary

SESSION-SUMMARY-2026-02-14.md described DONE work (local E2E deployment
proof, commit ece13ac) and a since-resolved GitLab push procedure. Per
estate cleanup policy, dated session notes older than 2026-04-21 that
describe completed work are removed (CHANGELOG/README/ROADMAP/PROOF-NEEDS
remain authoritative).

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

Author: hyperpolymath