The Import-LIB-KiCad-Plugin documentation registers third-party libraries
using `${KICAD_3RD_PARTY}` (without a KiCad-version prefix). KiCad accepts
both unprefixed and version-prefixed forms in lib-tables, and the analogous
`KICAD_SYMBOL_DIR` was already handled in `library_symbol.py`'s env-var
dictionary.
`KICAD_3RD_PARTY` was missing from both `_resolve_uri` env-var dictionaries
(in `python/commands/library.py` and `python/commands/library_symbol.py`),
so lib-table rows authored as `${KICAD_3RD_PARTY}/Foo.kicad_sym` or
`${KICAD_3RD_PARTY}/Foo.pretty` failed to substitute, were treated as
non-existent paths, and disappeared from `list_symbol_libraries` /
`list_libraries` results — even though KiCad's GUI showed them correctly.
Changes:
- Add `KICAD_3RD_PARTY` to both `_resolve_uri` env-var dictionaries.
- Add `KICAD_3RD_PARTY` fallback in
`SymbolLibraryManager._find_3rd_party_dir`.
- Refactor `LibraryManager._find_kicad_3rdparty_dir` to check all four
env-var forms (KICAD10/9/8_3RD_PARTY + KICAD_3RD_PARTY) consistently.
- Add regression tests in `tests/test_kicad_3rd_party_env_resolution.py`.
Reproduces with:
- Set `KICAD_3RD_PARTY` env var in the MCP server's environment.
- Register `(lib (name "Foo") (type "KiCad") (uri "\${KICAD_3RD_PARTY}/Foo.kicad_sym") ...)` in the global sym-lib-table.
- Place a real `Foo.kicad_sym` at the resolved path.
- Before: `list_symbol_libraries` does not return `Foo`.
- After: `Foo` is listed.