Bridge-IN E2E: provision a dedicated WalletConnect projectId + re-enable gating

**Bridge-IN E2E is currently non-blocking** (`continue-on-error` added in #402) because it fails on `WS close 3000 ("Project not found")` — the WalletConnect relay rejects the app's projectId (the shared free-tier fallback `b54ef53f…`, since no `WALLETCONNECT_PROJECT_ID` secret is set). It's a suspended/rate-limited projectId, not a code bug, and it has never passed on main. Bridge-in is currently hidden from users (`isBridgeDepositEnabled`).

### To restore blocking coverage
1. Provision a dedicated WalletConnect Cloud projectId (ideally two — one for the app, one for the headless counterparty, to halve per-projectId relay load).
2. Add them as CI secrets: `WALLETCONNECT_PROJECT_ID` and `WC_COUNTERPARTY_PROJECT_ID` (the workflow + `wc-counterparty.ts` already read these).
3. Remove the `continue-on-error: true` on the "Run bridge-IN deposit E2E" step in `.github/workflows/e2e-bridge-in.yml`.

The handshake-retry resilience (#401) is already in place for transient relay subscribe timeouts once the projectId is valid.