build(config): prepare ReVoltVPN 3.3.5 release

Bump the app version and document the 3.3.5 changes while preserving the published 3.3.4 release history.

CHANGELOG.md

@@ -5,6 +5,47 @@ Versions follow [semver](https://semver.org/): MAJOR.MINOR.PATCH
 
 ---
 
+## [3.3.5] — 2026-09-03
+
+### Added
+- **OS-level session-expiry enforcement.** The native VPN service now enforces the
+  server deadline with both a monotonic in-process handler and `AlarmManager`, so
+  expiry does not depend on the Flutter UI process staying alive.
+- Only the non-secret runtime generation token and absolute expiry timestamp are
+  persisted app-private for the OS alarm. Per-session VLESS UUID/SOCKS credentials
+  remain memory-only; if Android cannot redeliver the original start intent, the
+  runtime fails closed instead of reconstructing a tunnel from secrets on disk.
+- A successful support reward now requests an immediate control-plane refresh so the
+  extended deadline is pushed to the native service without waiting for the next poll.
+
+### Fixed
+- **Session clock reattach race.** `SessionTimer` is eager and evaluates the current
+  VPN state once after construction, so a UI process attaching to an already-live
+  tunnel no longer leaves the countdown at `00:00:00`.
+- Forced support sync no longer disappears behind an already-running periodic sync;
+  it waits for the active request and then performs a fresh control-plane refresh.
+- VPN permission requests now fail with `NO_ACTIVITY` during Android activity detach
+  instead of dereferencing a null Activity.
+- Receiver cleanup logs lifecycle races instead of silently swallowing them.
+- An early/stale session-expiry alarm no longer leaves an otherwise unused service
+  process running.
+
+### Changed
+- Unknown/obsolete persisted connection-mode labels, including the old `ass`/`auto`
+  values, now fail closed to TUN. Only the explicit current `proxy` value restores
+  SOCKS5 mode.
+- App version is `3.3.5+31`.
+
+### Security
+- Existing AdMob bypass/callback behavior is intentionally unchanged.
+- Build-time mutation of the global Flutter pub cache remains removed; the hardened
+  `flutter_vless_android` 1.1.5 source remains vendored and immutable during builds.
+- Full IPv4/IPv6 TUN routing, fail-closed DNS/TUN setup, authenticated ephemeral
+  loopback SOCKS5, generation-scoped STOP/state handling, production config pinning,
+  dependency verification, R8 gates and updater host allowlists remain in force.
+
+---
+
 ## [3.3.4] — 2026-09-02
 
 ### Added

pubspec.yaml

@@ -15,7 +15,7 @@ publish_to: "none" # Remove this line if you wish to publish to pub.dev
 # In iOS, build-name is used as CFBundleShortVersionString while build-number used as CFBundleVersion.
 # Read more about iOS versioning at
 # https://developer.apple.com/library/archive/documentation/General/Reference/InfoPlistKeyReference/Articles/CoreFoundationKeys.html
-version: 3.3.4+30
+version: 3.3.5+31
 
 environment:
   sdk: ">=3.0.0 <4.0.0"