Verify 2026-09-01 upstream sync native gates

[berghtho]

Upstream sync upstream-sync/2026-09-01 integrates 2daff8c25adf701fddd062ae93b94cc57d420ec2..b883fc066ea5c9bebbe1c3e9b4bc2471aab3685f at merge commit acce690419d10f318b389790f44aa1043a90ea4d (68 commits, 400 files).

The Windows validation is broad, but this batch changes native iOS presentation/composer code, mobile native patches, and native/resource-monitor. Actions are disabled, so the following gates need a suitable host before the sync PR can merge:

• macOS + Xcode: install with the pinned Node/pnpm versions and build/test the iOS app/native modules
• Run SwiftLint plus available Kotlin native lint (ktlint/detekt)
• Run cargo test --locked --manifest-path native/resource-monitor/Cargo.toml
• Recheck the inherited GitManager force-push fixture on a supported Linux setup; Windows reached only a CRLF assertion, while the available Ubuntu environment failed earlier during fixture fetch

Already verified: frozen install and supply-chain policy; 2,363 passing tests on Windows; 16/16 Claude/Grok tests and 14/14 AssetAccess tests on Ubuntu; all changed package typechecks; mobile static check; targeted lint/format; Riker baseline and Lead Agent tests.

Do not mark the sync PR ready or merge until these boxes are resolved.