feat: add footprint + symbol creator tools
Footprint tools:
- create_footprint: generates .kicad_mod via f-string (SMD/THT, courtyard, silkscreen, fab)
- edit_footprint_pad: updates size/position/drill/shape in-place
- list_footprint_libraries: scans .pretty directories
- register_footprint_library: adds entry to fp-lib-table
Symbol tools:
- create_symbol: generates .kicad_sym with pins, rectangles, polylines
- delete_symbol: removes symbol from library
- list_symbols_in_library: lists all symbols in a .kicad_sym file
- register_symbol_library: adds entry to sym-lib-table
Also:
- Fix footprint format version: 20250114 (schematic) -> 20241229 (footprint)
- Two MCP prompts: create_footprint_guide + footprint_ipc_checklist
Live tested: TMC2209 footprint (19 pads), R_0603_Test, edit_footprint_pad,
TMC2209_Custom symbol with pins all confirmed in KiCAD 9
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