This release closes a vulnerable dependency, removes committed TURN credentials, and tightens production logging.
### Security
- Upgraded DOMPurify from 3.4.4 to a patched release, resolving a high-severity XSS advisory (GHSA-87xg-pxx2-7hvx) in the incoming-message sanitizer.
- Upgraded the `esbuild` build dependency to clear a high-severity advisory in the toolchain. `npm audit` now reports zero vulnerabilities.
- Stopped tracking `config/ice-servers.js` (operator TURN credentials) in Git and added `config/ice-servers.example.js` as a template. Operators must rotate any previously committed credentials.
- Removed temporary debug branches from the production logger so it no longer prints error context or info/debug payloads — only an opaque error code.
### Documentation
- Updated the supported-release table in `SECURITY.md` to the v4.8.x line.
- Synchronized the version string across the header, manifest, README, and in-app initialization message.
This patch completes the mandatory receiver-consent gate for incoming file transfers and resolves a callback ownership conflict that caused every incoming file request to be silently auto-rejected.
### Fixed
- Wired up the missing fourth `onIncomingFileRequest` callback in the main `setFileTransferCallbacks` call. Without it, `handleFileTransferStart` always saw `null` for the consent handler and auto-rejected every incoming file silently.
- Removed independent callback registration from `FileTransferComponent`. The component was overwriting the application-level callbacks on mount and nulling all four on unmount, which destroyed the progress, received, and error handlers whenever the panel was hidden.
- Centralized incoming-consent state (`pendingIncomingFiles`) in the root application component so consent prompts appear regardless of whether the file-transfer panel is currently visible.
- Auto-opens the file-transfer panel when an incoming request arrives so the user sees the Accept / Reject prompt immediately.
- Added `getReceivedFileObjectURL` / `revokeReceivedFileObjectURL` helpers to `EnhancedSecureWebRTCManager` so the panel can offer a download button for completed transfers without relying on captured callback closures.
- Updated `file-transfer-ui-cleanup` regression test to match the new single-owner callback architecture.
### Security
No change to the cryptographic or transport-level security model. Sender chunks are still gated behind an explicit `file_transfer_response` from the receiver before any data is transmitted.
This patch release strengthens SecureBit.chat across verification, sanitization, privacy, transport abuse resistance, cache safety, and repository hygiene.
### Security hardening
- Bound SAS verification to the actual DTLS fingerprint strings of both peers.
- Replaced regex-based chat sanitization with DOMPurify-backed sanitization.
- Made WebRTC privacy mode explicit and kept relay-only state synchronized at runtime.
- Removed production exposure of internal debug/control hooks.
- Added receiver-side rate limiting for inbound chat messages.
- Added receiver-side throttling for inbound file chunks.
### Runtime and privacy safety
- Hardened service-worker caching so only explicitly allowlisted safe assets are cached.
- Removed an untracked disconnect timer so teardown no longer leaves delayed callbacks behind.
- Preserved relay-only TURN behavior while making privacy implications clearer when relay-only mode is disabled or TURN is unavailable.
### Repository hygiene
- Stopped tracking `node_modules` in Git so platform-specific dependency binaries no longer pollute the repository or break cross-platform builds.
