[blessdyb]

Summary

• eliminate all first-party warnings from FlowlightTests and enable warnings-as-errors for the test bundle
• extend the durable Swift warning gate to test sources and enforce it in CI and release test logs
• advance the app to 0.15.10 build 57 while preserving the direct-distribution system extension at 0.15.4 build 26

Verification

• real pre-fix build-for-testing log: checker rejected all 18 first-party test warnings with status 1
• exact-head suite: 825 tests, 0 failures; warning checker passed
• direct Release and Mac App Store builds: succeeded, warning checker passed, universal x86_64/arm64
• Xcode project drift, warning fixtures, notarization fixtures, localization, signed catalog, reproducible site, site validator, release-note extraction, and git diff --check: passed

🤖 Generated with Claude Code