Add netlists and fix layout templates for svbpcb backend

[ducky64]

• Change placement data structure to not require name on elements, storing elements as a list
• Add a blackbox block for arrange_blocks, used to place layout templates
• Add _svgpcb_bbox to the template API, to return a bounding box to be used in initial placement
• Refactors svgpcb template APIs to assert instead of returning optional, in most cases those errors cannot be handled

[Copilot]

Pull Request Overview

Updates all example .svgpcb.js files to align with the new backend API by removing explicit element names, using generic sequential IDs, and adding explicit netlist definitions.

• Renamed component variables (e.g., usb_conn, reg_ic) to generic IDs (J1, U1, R1, etc.) with inline comments preserving the original logical names.
• Inserted board.setNetlist([...]) calls at the end of each example to define nets explicitly.
• Removed now-unnecessary id string names and updated templates to the asserted API.

Reviewed Changes

Copilot reviewed 50 out of 54 changed files in this pull request and generated 2 comments.

Show a summary per file

File	Description
examples/TofArray/TofArray.svgpcb.js	Renamed elements to generic IDs and added netlist
examples/TestBlinkyWithSchematicImport/TestBlinkyWithSchematicImport.svgpcb.js	Generic IDs and netlist block added
examples/TestBlinkyWithModeledSchematicImport/TestBlinkyWithModeledSchematicImport.svgpcb.js	Generic IDs and netlist block added
examples/TestBlinkyWithLibraryExport/TestBlinkyWithLibraryExport.svgpcb.js	Generic IDs and netlist block added
examples/TestBlinkyWithLibrary/TestBlinkyWithLibrary.svgpcb.js	Generic IDs and netlist block added
examples/TestBlinkyPacked/TestBlinkyPacked.svgpcb.js	Generic IDs and netlist block added
examples/TestBlinkyMicro/TestBlinkyMicro.svgpcb.js	Generic IDs and netlist block added
examples/TestBlinkyExpanded/TestBlinkyExpanded.svgpcb.js	Generic IDs and netlist block added
examples/TestBlinkyEmpty/TestBlinkyEmpty.svgpcb.js	Added empty netlist call
examples/TestBlinkyComplete/TestBlinkyComplete.svgpcb.js	Generic IDs and netlist block added
examples/TestBlinkyChain/TestBlinkyChain.svgpcb.js	Generic IDs and netlist block added
examples/TestBlinkyBasicBattery/TestBlinkyBasicBattery.svgpcb.js	Generic IDs and netlist block added
examples/TestBlinkyBasic/TestBlinkyBasic.svgpcb.js	Generic IDs and netlist block added
examples/TestBlinkyArray/TestBlinkyArray.svgpcb.js	Generic IDs and netlist block added
examples/TestBlinkyImplicit/TestBlinkyImplicit.svgpcb.js	Generic IDs and netlist block added

Comments suppressed due to low confidence (1)

examples/TofArray/TofArray.svgpcb.js:4

• [nitpick] The generic variable name H1 may be ambiguous when scanning code. Consider using a more descriptive identifier (e.g., toolingHole1) to improve readability.

const H1 = board.add(JlcToolingHole_1_152mm, {

[Copilot]

[nitpick] Missing semicolon after the board.setNetlist([...]) call. Consider adding a trailing semicolon for consistent statement termination.

[Copilot]

[nitpick] The inline netlist definition is quite large. Consider extracting it into a separate constant or JSON file to declutter the example and improve readability.