fix(android): preserve More in back navigation

[SpurgtBror]

What this PR does

Preserves the Android More page in the navigation back stack when one of its 27 destination rows is opened.

More became a real NavHost destination in 798567e1, but its rows continued using navigateTopLevel(). That helper pops to the graph start destination (Today) before navigating, so the stack became Today → destination and Android Back skipped More.

The shared More callback now performs an ordinary push:

before: Today → More; More row → Today → destination
after:  Today → More → destination

Bottom-tab selections keep their existing single-top state save/restore behavior. Contextual top-level links elsewhere are untouched because their section-switching semantics are independent of this report.

A focused source-contract regression test pins both sides of that boundary: every generated More row still uses the shared push callback, while bottom tabs continue through navigateTopLevel().

No BLE, protocol, persistence, analytics, localization, public API, or visual/layout changes.

Type of change

• Bug fix
• New feature
• Refactor / cleanup
• Documentation
• CI / tooling

How it was tested

Added MoreNavigationContractTest.moreRowsPushWhileBottomTabsRemainTopLevel, which checks that:

• the More route uses nav.navigate(it);
• it cannot regress to nav.navigateTopLevel(it);
• all generated More rows retain the shared callback;
• bottom-tab selections retain navigateTopLevel().

Local source checks:

• python3 Tools/doc_comment_lint.py — pass
• python3 Tools/i18n_audit.py --ci origin/main — pass
• git diff --check — pass
• GitHub Android CI: assembleFullDebug + testFullDebugUnitTest — pass

Android compile/unit-test commands were attempted but could not start because this workspace has no Java runtime or Android SDK:

ERROR: JAVA_HOME is not set and no 'java' command could be found in your PATH.

The PR is therefore opened as a draft pending ./gradlew testFullDebugUnitTest, ./gradlew compileFullDebugKotlin, and Android emulator/device verification.

Manual acceptance matrix for that verification:

• More → one destination from each group → Back returns to More.
• More → Settings → Test Centre/Backup & Sync → Back returns to Settings, then More.
• More → Health → vital detail → Back returns to Health, then More.
• Back from More returns to Today.
• Bottom-tab state save/restore remains unchanged.
• Settings opened from the Today avatar still returns to Today.

Checklist

• Swift package tests pass for any package I touched (swift test in Packages/<name>) — no Swift packages touched
• Android unit tests pass if I touched android/ (./gradlew testFullDebugUnitTest) — GitHub Android CI
• No new build warnings introduced — awaiting Android compilation
• UI changes use only StrandDesign tokens — no visual/layout changes
• No hardcoded hex frame bytes; protocol facts live in the schema / decoders — no protocol changes
• Follows the conventions in docs/CONTRIBUTING.md
• I did not commit generated output (Strand.xcodeproj/) or any secrets/keystores

Related issues

Closes #1570

Related: #397 proposes a larger replacement of the current More page.