feat(timeline): DAWproject linear-subset XML importer

[shipyard-local]

What

Foundation of Phase-3 item #7 (DAWproject import): a DAWproject project.xml → timeline-model importer for a documented linear subset.

import_dawproject_xml() parses the XML with pugixml (DOM traversal) and assembles a Project through the timeline model's public construction API. It is a pure model consumer — no model-layout change.

Documented subset (the DoD "documented subset loads")

• <Project version="1.x"> root
• <Transport> single <Tempo unit="bpm"> + <TimeSignature> → single-point tempo/meter maps at bar one
• flat <Structure> <Track> elements (no nested group tracks)
• <Arrangement> <Lanes timeUnit="beats"> → per-track <Lanes track><Clips><Clip time duration> with <Notes> or <Audio><File> content

Beats are quarter notes → canonical ticks via kTicksPerQuarter. Audio clips reference a deduplicated MediaAsset; its durable ContentHash is provisionally derived from the package path (bytes live in the not-yet-unzipped container), with the path preserved as a PackageRelative AssetLocator hint.

Fails closed — no silent drops

Anything outside the subset (<Warps>, nested group tracks, timeUnit="seconds", unknown arrangement/lane timelines, missing required attributes, out-of-range note pitch/velocity, dangling track refs, duplicate track ids) is rejected with a descriptive DawProjectImportError, never partially imported.

Where it lives — and why not src/

The importer is in core/timeline/import/, not core/timeline/src/. The web-timeline-source-closure gate sweeps every core/timeline/src/*.cpp into the WAM/WebCLAP wasm DSP lanes, which deliberately do not link pulp-runtime. The importer's pugixml dependency has no place in a browser RT-DSP binary, so keeping it out of src/ keeps pugixml out of wasm. The timeline and web-plugins skills record this constraint.

Tests

test/test_timeline_dawproject_import.cpp (72 assertions, 4 cases):

• committed fixture linear_subset.dawproject.xml → import → assert track count/order, clip placements (ticks), asset dedup, notes, tempo/meter, sequence duration
• silent-drop guard: committed out_of_subset.dawproject.xml (a <Warps> clip) must be rejected, not imported as an empty clip
• 11 malformed/out-of-subset sub-cases (parse error, wrong root, bad version, non-bpm tempo, seconds timing, nested group track, duplicate id, dangling ref, missing attr, bad pitch, missing <File>, unsupported arrangement timeline)
• empty-project-with-defaults case

Deferred (follow-ups, out of scope here)

• .dawproject ZIP unwrap + real-byte content hashing
• non-linear / clip-launch arrangement mapping
• the pulp import CLI verb (tools/cli)
• full parity-suite integration

🤖 Generated with Claude Code

https://claude.ai/code/session_01TVQHcnbg3t6TvXsdv6gXhS

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🔎 Provenance

Agent	claude
Machine	m3
Tab	Timeline v3
Directory	/Volumes/Workshop/Code/pulp-dawproject
Session	c66f4a64-25ea-42e5-b184-d48611a066a2

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_{stamped 2026-07-22 13:02 UTC}