chore: v1.9.33 — idle keepalive backoff

Ship PR #1322 by @yyoyoian-pixel: Full Tunnel idle sessions now reduce empty keepalive request load, while mixed deployments keep polling so long-poll-capable peers can continue delivering remote-to-client data.

Local verification:
- cargo test --lib
- cargo build --release
- cargo build --bin mhrv-rs-ui --release --features ui

Author: therealaleph

Cargo.lock

@@ -1,6 +1,6 @@
 [package]
 name = "mhrv-rs"
-version = "1.9.32"
+version = "1.9.33"
 edition = "2021"
 description = "Rust port of MasterHttpRelayVPN -- DPI bypass via Google Apps Script relay with domain fronting"
 license = "MIT"

Cargo.toml

@@ -14,8 +14,8 @@ android {
         applicationId = "com.therealaleph.mhrv"
         minSdk = 24 // Android 7.0 — covers 99%+ of live devices.
         targetSdk = 34
-        versionCode = 164
-        versionName = "1.9.32"
+        versionCode = 165
+        versionName = "1.9.33"
 
         // Ship all four mainstream Android ABIs:
         //   - arm64-v8a      — 95%+ of real-world Android phones since 2019

android/app/build.gradle.kts

@@ -0,0 +1,5 @@
+• در حالت Full Tunnel، نشست های کاملا idle حالا keepalive خالی را با backoff شدیدتر می فرستند و وقتی همه deploymentها legacy تشخیص داده شوند، بعد از idle شدن دیگر poll خالی پشت سر هم نمی زنند. این کار مصرف request روی Apps Script و `tunnel-node` را برای اتصال های بی کار کمتر می کند. (PR [#1322](https://github.com/therealaleph/MasterHttpRelayVPN-RUST/pull/1322) از @yyoyoian-pixel)
+• برای fleetهای mixed که هنوز حداقل یک deployment با long-poll سالم دارند، کلاینت همچنان poll خالی را ادامه می دهد تا round-robin بتواند به همان peer سالم برسد و داده remote→client گیر نکند.
+---
+• In Full Tunnel mode, fully idle sessions now use a stronger empty-keepalive backoff, and when every deployment is detected as legacy they stop sending repeated empty polls after going idle. This reduces Apps Script and `tunnel-node` request load for quiet connections. (PR [#1322](https://github.com/therealaleph/MasterHttpRelayVPN-RUST/pull/1322) by @yyoyoian-pixel)
+• For mixed fleets where at least one deployment still has healthy long-poll support, the client keeps emitting empty polls so round-robin can still reach that healthy peer and remote→client data does not stall.