chore: record ZIP artifact task completion

.trellis/tasks/08-26-rc-p5b-zip-import/design.md

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+# P5B ZIP Import Design
+
+`scripts/lib/native-road-package.js` becomes the single host adapter. It resolves the config-relative
+ZIP path, hashes it, validates central-directory entry names and metadata, and extracts only accepted
+regular files to `_pipeline/native-road-import/<sha256>/`. It validates the unpacked manifest and
+returns an immutable package descriptor:
+
+```text
+{ zipFile, zipRecord, rootDir, manifest, records }
+```
+
+The descriptor replaces `area.outputs.nativeRoadDir` as native input for Blender, native preview traffic,
+diagnostics and stage manifests. The configured ZIP and unpacked cache are inputs, never published area
+outputs. Cache invalidation is by ZIP SHA-256; cleanup only deletes importer-owned hash directories.
+
+The importer rejects any non-root-flat layout, duplicate path, symlink, unsupported compression/error,
+path traversal, invalid manifest, area mismatch or declared/published mismatch before Blender starts.
+The native compiler CLI dependency and host-owned `nativeRoad` compilation options are removed. Legacy
+`osm2streets` remains an explicit separate provider.