- tests/e2e/wallet-connect.spec.ts: wallet connection via Freighter, JWT
  storage, authenticated page access
- tests/e2e/trade-lifecycle.spec.ts: full lifecycle (create trade, deposit,
  confirm delivery, dispute, combined end-to-end)
- tests/e2e/dispute-resolution.spec.ts: mediator dashboard, dispute resolution
  with equal split, evidence submission
- Updated playwright.config.ts to include tests/e2e in the test directory

Covers: connect wallet, create trade, deposit, confirm delivery, dispute

- state_machine_fuzz_tests.rs includes 6 new property-based fuzz modules:
  1. prop_state_machine_random_ops: random sequence of lifecycle operations
  2. prop_fuzz_addresses_in_create_trade: invalid/self-referencing addresses
  3. prop_storage_integrity_rapid_transitions: rapid state transitions
  4. prop_resolve_dispute_fuzz: all loss-sharing param combinations
  5. prop_boundary_fuzz: edge-case amounts with extreme fee rates
  6. prop_many_trades_rapid_creation: rapid multi-trade creation & counters

Builds on existing QuickCheck infrastructure (bps_fuzz_tests.rs)

- frontend/tests/pact/trades.pact.test.ts: consumer-side Pact tests covering
  all trades API endpoints (create, deposit, confirm, release, dispute,
  get, list, stats) using PactV3 + MatchersV3
- backend/src/__tests__/trades.pact.verify.test.ts: provider-side verification
  against generated pact files with state handlers
- Installed @pact-foundation/pact v17 in both frontend and backend

This establishes the contract testing pipeline between frontend (consumer)
and backend (provider) for the trades API.

- Change all CI gates (frontend, backend, mobile) from npm ci to
  pnpm install --frozen-lockfile (project uses pnpm as package manager)
- Use pnpm/action-setup for pnpm bootstrapping and pnpm caching
- Remove npm audit and lockfile verification steps (not applicable with pnpm)
- Fix contract deployment safety check regex to accept both
  ['cdylib', 'rlib'] and ['rlib'] crate-type formats