Speed up sparse delta base materialization

[peters]

Summary

• Prefer the active installed app as the base archive for sparse/file-ops delta materialization.
• Keep byte-exact delta formats on the release-graph restore path.
• Emit specific apply-phase status labels for base restore, target delta apply, rebuilt package write, and extraction.
• Retry with the release-graph base if an installed-app base produces an invalid target archive, preserving the previous successful path before falling back to a full package.

Fixes #185.

Performance Notes

Benchmarked locally with a real large downstream app cache and release index, using a temp store/cache and excluding the warmed current full archive where noted.

• Cold long-chain release-graph restore: exceeded 12 minutes and was terminated at 720 seconds.
• Bounded release-graph restore from the latest cached full checkpoint plus two sparse deltas: 117,371 ms for a 344,062,822 byte rebuilt full archive.
• Installed-app synthesis from the active app tree: 18,024 ms for a 317,602,882 byte archive.
• The live installed archive did not have a compressed SHA match with the release index, so the implementation keeps the safe release-graph retry when target delta verification fails.

Validation

• ./scripts/sync-surge-core-vendor.sh --check
• ./scripts/check-version-sync.sh
• cargo fmt --all -- --check
• RUSTFLAGS="-D warnings" cargo test -p surge-core test_download_and_apply_delta -- --nocapture
• RUSTFLAGS="-D warnings" cargo test --workspace
  • First sandboxed run failed only at commands::lock::tests::acquire_and_release_use_manifest_lock_server with Operation not permitted while binding a local listener.
  • Reran the same command with elevated permissions: passed.
• cargo clippy --all-targets --all-features -- -D warnings
• cargo clippy --workspace --lib --bins --examples -- -D warnings -D clippy::unwrap_used -D clippy::expect_used
• cargo clippy --workspace --all-targets --all-features -- -D warnings -W clippy::pedantic
• dotnet format dotnet/Surge.slnx --verify-no-changes
• dotnet test dotnet/Surge.slnx --configuration Release