feat: MCP STEP import, forward tool-script dump, and solid compare

[jeffglousher]

Summary

• Add MCP solid_import_step / solid_edit_import_step over the existing import_step body feature (dumb reference solid + stored STEP bytes). This does not reverse-engineer sketch/extrude history from B-rep.
• Add cad_script to dump this process’s successful mutating tools/call sequence as { "calls": [ { "name", "arguments" } ] } (forward record; skips inspect/export, failed calls, and cad_script itself).
• Add cad_compare_solids to summarize solid_scene body count plus per-body bbox / vertex / triangle counts so a rebuilt history can be checked against an imported reference.

Test plan

• cargo test --manifest-path mcp-server/Cargo.toml --bin nbcad-mcp (29 passed, including mcp_import_step_records_forward_script)
• rustfmt on edited MCP sources
• Reviewer: export a box via MCP, cad_new_project or a fresh process, solid_import_step, confirm one body, cad_script contains solid_import_step, cad_compare_solids reports mesh counts

[jackControls]

The forward script is not portable after a snapshot attach. records_in_script at mcp-server/src/main.rs:2617 excludes cad_detach but still records successful cad_attach and cad_refresh calls. cad_script can therefore begin with an ephemeral session UUID and depend on mutable files outside the script; replaying it on another machine/process can fail immediately or load a different snapshot, contrary to the advertised successful mutating tool sequence.

Please exclude cad_attach/cad_refresh as session-control reads, or convert attach into a portable cad_load_project_model entry containing the loaded model and define when the trace resets. Add a regression that attaches and refreshes a snapshot, performs a modeling operation, and verifies the dumped script contains only replayable modeling state. Requesting changes; I did not merge.

[jeffglousher]

Addressed the CHANGES_REQUESTED review:

• records_in_script now excludes cad_attach / cad_refresh alongside cad_detach (session-control reads), so cad_script stays portable modeling ops only — no ephemeral session UUID as a required first call.
• Documented that contract in docs/mcp-harness.md / knowledge mcp-harness.
• Regression cad_script_excludes_attach_refresh_after_snapshot_modeling: attach + refresh snapshot, mirror, dump script — asserts no attach/refresh/detach and no session UUID dependency; modeling call present.
• Also finished local solid_move_copy / solid_edit_move_copy ToolSpec + disclosure + unit test (schema matches MoveCopyBodyRequest).

cargo test --manifest-path mcp-server/Cargo.toml --bin nbcad-mcp: 34 passed. Rebased onto current main. Ready for another look — please re-review when you can.

[jackControls]

The UUID leak is fixed, but the dumped script is still not replayable after attach/refresh.

cad_attach and cad_refresh replace self.manager from model.json (load_snapshot_model), while records_in_script now omits both operations and tool_trace is neither reset nor seeded with a portable baseline. In the new regression, the emitted script therefore contains solid_mirror with a body ID that only exists in the omitted snapshot. Replaying those calls on a fresh CadServer fails because the script never creates that body. The test only asserts that attach/refresh/UUID are absent; it never replays the returned calls.

Please make snapshot loads establish a replayable trace baseline—e.g. clear/seed the trace with cad_load_project_model carrying the loaded model_json, with a defined refresh policy—and add a test that executes every emitted call against a fresh server and compares the result. Requesting changes on the current head; I did not merge.

[jeffglousher]

Addressed the latest CHANGES_REQUESTED:

• On successful snapshot load (cad_attach / cad_refresh → load_snapshot_model), clear tool_trace and seed cad_load_project_model with the loaded model_json. Refresh replaces that baseline the same way (drops any post-attach mutates that are no longer in manager).
• cad_attach / cad_refresh / cad_detach still omitted from the dumped script; baseline is the portable load call that already existed.
• Regression cad_script_after_attach_refresh_replays_on_fresh_server: attach + refresh, mirror, dump script, execute every emitted call on a fresh CadServer, compare cad_compare_solids metrics. Also asserts no session UUID / attach/refresh in the script.

cargo test --manifest-path mcp-server/Cargo.toml --bin nbcad-mcp: 34 passed. Please re-review when you can — do not merge from my side.

[jackControls]

Re-reviewed at 52266b2. Attach/refresh now seed replay with a portable snapshot, session-only calls remain excluded, and the regression test replays the complete dump on a fresh server. I also ran the full MCP server suite locally: 34/34 tests passed. Approved.

[jackControls]

Re-reviewed at 52266b2. Attach and refresh now seed replay with a portable cad_load_project_model snapshot, session-only calls remain excluded, and the regression test replays the complete dump on a fresh server. I also ran the full MCP server suite locally: 34 of 34 tests passed. Approved.