feat(mcp): host-neutral assembly component tools

[jeffglousher]

Summary

• Expose host-neutral assembly ops as first-class MCP tools (Direct → host::handle), so agents can build real assemblies (NIST FTC / print-kit style) without hand-editing model.json.
• Tools: assembly_document, assembly_solution, assembly_create_component, assembly_update_component, assembly_create_occurrence, assembly_update_occurrence, assembly_set_occurrence_pose, assembly_set_occurrence_grounded.
• New assembly focus pack in disclosure (ribbon-aligned); schemas match CreateComponentRequestDto / occurrence / pose / grounded DTOs.
• Out of scope: joints (assembly_create_joint / delete) deferred to a follow-up when schemas stay small.

Test plan

• cargo test in mcp-server (32 passed), including assembly_component_occurrence_grounded_roundtrip (new project → extrude box → create component absorb → set pose/grounded → assembly_document shows component; headless, no attach)
• Registry / focus-pack matrix counts updated (113 modeling tools)

[jackControls]

The update ToolSpec schemas permit destructive partial replacement.

assembly_update_component requires only id and name, but deserialization defaults omitted body_ids to [], the local coordinate system to identity, and promoted to false. AssemblyModel::update_component then replaces the whole definition. A valid rename-only call can therefore silently remove every body from the component and reset its coordinate system.

Likewise, assembly_update_occurrence requires only id, name, and component_id; omitted parent, pose, visibility, and grounded values deserialize to defaults before the whole occurrence is replaced. A rename-only call can reparent/reposition/show/unground an occurrence.

Please either require every replacement field in both schemas or introduce patch DTOs that preserve omitted values, with rename-only regression tests. Requesting changes; I did not merge.

[jeffglousher]

Addressed CHANGES_REQUESTED with patch DTOs (Option B): ComponentDefinitionPatchDto / ComponentOccurrencePatchDto — only id required; host update_component / update_occurrence preserve omitted fields. ToolSpecs updated. Rename-only MCP tests + assembly unit test assert bodies/LCS/pose/parent/visibility/grounded unchanged. Not merging.

[jackControls]

Re-reviewed at b6d6543. The patch DTO semantics, omitted-field preservation, and explicit-null parent clearing now look correct; the targeted assembly and MCP preservation tests pass locally. The remaining blocker is the failed required MCP check: reports formatting diffs in and . Please run and push the result.

[jackControls]

Re-reviewed at b6d6543. The patch DTO semantics, omitted-field preservation, and explicit-null parent clearing now look correct; the targeted assembly and MCP preservation tests pass locally. The remaining blocker is the failed required MCP check: cargo fmt --all -- --check reports formatting diffs in crates/assembly/src/lib.rs and crates/sketch/src/lib.rs. Please run cargo fmt --all and push the result.

[jeffglousher]

fmt only

[jeffglousher]

Rebased onto upstream/main (5248caf, includes #61). New tip: 695b410.

• Resolved disclosure/main MODELING_TOOL_COUNT → 117 (109 + 8 assembly) with +21 control helpers.
• Kept patch DTOs + rename preservation tests; cargo fmt --all clean.
• Tests: mcp-server 37 passed (no mcp-mutate crate on this branch).
• History rewritten — please re-review.

[jackControls]

Re-reviewed at 695b410. The patch DTOs now preserve omitted component and occurrence fields, explicit null correctly clears an occurrence parent, validation remains transactional, and formatting is clean. Local verification passed: 32 assembly tests and all 37 MCP-server tests. Approved.