[D031] [CHORE] Submit Soroban Security Audit Bank application

[ezedike-evan]

Description
Follow-on to #D030: the actual submission action.
Requirements

• Submit the prepared application materials through the Audit Bank's official channel.
• Record confirmation of submission (ticket/reference number if provided) for tracking.
  Acceptance Criteria
• Application submitted; confirmation reference logged in the project's grant tracking doc.
  Estimated File Changes: 1 (docs/grants/AUDIT_BANK_APPLICATION.md)
  Labels: chore, epic/docs-community, difficulty/good-first-issue
  Milestone: H1 Rung 1 — Data Infra + Grant