Add capsule navigation simplification for voxel output

[slimbuck]

Summary

Adds a nav simplification pass to the voxel pipeline that carves away geometry unreachable by an upright capsule, reducing voxel data size for navigation use cases.

Algorithm

1. Build a dense bitfield grid from the sparse block accumulator
2. Dilate solid by the capsule shape (Minkowski sum via 3 separable 1D sliding-window passes)
3. BFS flood fill from a seed point to find all reachable capsule-center positions
4. Invert unreachable space to solid (negative space carving)
5. Erode back by capsule shape (Minkowski subtraction) to restore correct surface positions
6. Crop to bounding box of navigable cells

Changes

• New simplifyForCapsule function in src/lib/voxel/nav-simplify.ts with bitfield storage (1 bit/voxel) and ping-ponged buffers for memory efficiency
• Integrated into writeVoxel pipeline, gated by navCapsule/navSeed options
• CLI flags: --no-nav-simplify, --nav-capsule <height,radius>, --nav-seed <x,y,z>
• ProgressNode.depth property for nested progress indentation
• Exported simplifyForCapsule, NavSeed, and NavSimplifyResult from the public API
• Unit tests covering hollow boxes, seed validation, empty accumulators, single blocks, and unreachable regions

CLI defaults

• Navigation simplification is enabled by default for voxel output
• Capsule: height 1.6, radius 0.2
• Seed: origin (0, 0, 0)
• Disable with -n / --no-nav-simplify

[Copilot]

Pull request overview

Adds a capsule-based navigation simplification pass to the voxel output pipeline, aiming to carve away unreachable space (from a capsule-center flood fill) to reduce voxel data size for navigation use cases.

Changes:

• Introduces simplifyForCapsule (dense 1-bit voxel grid + dilation/BFS/invert/erosion + cropping) and exports it publicly.
• Integrates nav simplification into voxel writing, controlled via new options and CLI flags (--no-nav-simplify, --nav-capsule, --nav-seed).
• Adds unit tests covering several representative navigation/cropping scenarios.

Reviewed changes

Copilot reviewed 7 out of 7 changed files in this pull request and generated 5 comments.

Show a summary per file

File	Description
test/nav-simplify.test.mjs	New unit tests for capsule-based nav simplification behavior.
src/lib/writers/write-voxel.ts	Hooks nav simplification into the voxel write pipeline and adjusts progress step counting.
src/lib/write.ts	Wires library Options into writeVoxel including nav defaults/enablement.
src/lib/voxel/nav-simplify.ts	New implementation of the capsule navigation simplification algorithm.
src/lib/types.ts	Adds navSimplify, navCapsule, navSeed to public options type.
src/lib/index.ts	Exports simplifyForCapsule and related types from the public API.
src/cli/index.ts	Adds CLI flags + parsing for nav simplification; updates help text and Node logger wiring.

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[Copilot]

Pull request overview

Copilot reviewed 7 out of 7 changed files in this pull request and generated 2 comments.

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[Copilot]

Pull request overview

Copilot reviewed 7 out of 7 changed files in this pull request and generated 3 comments.

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[Copilot]

Pull request overview

Copilot reviewed 7 out of 7 changed files in this pull request and generated 2 comments.

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[Copilot]

Pull request overview

Copilot reviewed 7 out of 7 changed files in this pull request and generated 2 comments.

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[Copilot]

Pull request overview

Copilot reviewed 7 out of 7 changed files in this pull request and generated 2 comments.

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[Copilot]

Pull request overview

Copilot reviewed 7 out of 7 changed files in this pull request and generated 1 comment.

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[Copilot]

Pull request overview

Copilot reviewed 7 out of 7 changed files in this pull request and generated no new comments.

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