feat: add on-chain risk flags for programs and escrows

[daveades]

What

• Introduces on-chain, admin-controlled risk flags for both program escrows and bounty escrows.
• Adds a small bitmask enum (high risk, under review, restricted, deprecated) and audit events.
• Exposes new admin APIs to set/clear flags and keeps flags visible in program/escrow metadata.
• Adds tests for set/clear/visibility and documents semantics in contracts/RISK_FLAGS.md.

Why

• Risk assessments often live off-chain; on-chain flags provide portable signals for UIs and analytics.
• Admin-controlled + event-emitted changes make updates auditable and indexable.

Implementation Details

• Program escrow: risk_flags added to ProgramData, plus set_program_risk_flags / clear_program_risk_flags and
  ProgramRiskFlagsUpdated event.
• Bounty escrow: risk_flags added to EscrowMetadata, plus set_escrow_risk_flags / clear_escrow_risk_flags and
  RiskFlagsUpdated event.
• SDK: ProgramData now includes risk_flags in contracts/sdk/src/program-escrow-client.ts.
• Documentation: contracts/RISK_FLAGS.md.

Tests

• contracts/bounty_escrow/contracts/escrow/src/test_risk_flags.rs
• contracts/program-escrow/src/test_risk_flags.rs

Notes

• Flags are advisory signals; intended for UI/analytics prioritization, not enforcement.

Closes #613

[vercel]

@daveades is attempting to deploy a commit to the Jagadeesh B's projects Team on Vercel.

A member of the Team first needs to authorize it.

[Jagadeeshftw]

please resolve the conflicts

[Jagadeeshftw]

please resolve the conflicts