chore: bump versions to 1.7.10 (Cargo + Android) + fix Win7 i686 lockfile

Patch release for the changes shipped via #337 (Apps Script range
probe gzip-decoded body handling) and #344 (Android Paste button on
13+) plus a CI fix that restores the Win7 i686 binary missing from
v1.7.9 (Cargo.lock format mismatch with Rust 1.77).

The Cargo.lock version=4 (Rust 1.78+) wasn't readable by the pinned
1.77.2 toolchain on the i686 job. Workflow now regenerates the
lockfile with the pinned toolchain on that job only, leaving every
other target unaffected.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

android/app/build.gradle.kts

@@ -14,8 +14,8 @@ android {
         applicationId = "com.therealaleph.mhrv"
         minSdk = 24 // Android 7.0 — covers 99%+ of live devices.
         targetSdk = 34
-        versionCode = 154
-        versionName = "1.7.9"
+        versionCode = 155
+        versionName = "1.7.10"
 
         // Ship all four mainstream Android ABIs:
         //   - arm64-v8a      — 95%+ of real-world Android phones since 2019