fix: add macOS Apple Silicon support for VHDL and Verilog language servers

[alexmodrono]

Summary

This PR fixes several bugs that prevented TerosHDL from working correctly on macOS (particularly Apple Silicon), and fixes a formatter regression that affected all platforms.

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1. Bundle vhdl-ls v0.84.0 for macOS Apple Silicon + system binary fallback

The extension only shipped Linux/Windows binaries. macOS ARM64 users had no bundled server and no fallback path. Two changes:

• Bundle the vhdl_ls-aarch64-apple-darwin binary (v0.84.0) under server/vhdl_ls/
• If the bundled binary fails (wrong arch, missing, etc.), automatically try /opt/homebrew/bin/vhdl_ls, /usr/local/bin/vhdl_ls, and vhdl_ls in PATH
• Same fallback pattern applied to Verible

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2. Fix --libraries argument (directory vs. file path)

vhdl_ls 0.84.0 expects the --libraries flag to point to the directory that contains vhdl_ls.toml, not to the file itself. The previous code passed the full file path, causing:

Not a directory (os error 20)

on every VHDL file open, which prevented the bundled IEEE/STD library from loading and crashed the server.

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3. Fix context.asAbsolutePath() corrupting system binary paths

context.asAbsolutePath(str) calls path.join(extensionRoot, str). When str is already an absolute path like /opt/homebrew/bin/vhdl_ls, path.join prepends the extension directory, producing a broken path like /ext/path/opt/homebrew/bin/vhdl_ls.

Fix: resolve the bundled binary's absolute path once at startup and store it directly, so getServerOptionsEmbedded never needs to call asAbsolutePath.

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4. Fix work library name in generated TOML

vhdl_ls 0.84.0 rejects work as an explicit library name in project config TOML (it is a reserved identifier). When files in a project have logical_name = "work", get_toml() was emitting work.files = [...], causing:

Error loading vhdl_ls.toml: The 'work' library is not a valid library.

Fix: remap library name work → teroshdlDefault in project_manager.ts.

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5. Fix duplicate verible.restart command registration

The extension was registering the teroshdl.verible.restart command twice, which caused an activation error when opening Verilog/SV files. Removed the redundant empty registration.

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6. Initialise VHDL_LS_CONFIG temp file with valid content

The temp file used for VHDL_LS_CONFIG was created with an empty string, causing:

missing field `libraries`

on startup. The server would then fall through to auto-discover any vhdl_ls.toml in the workspace root, bypassing the project config entirely. Fix: initialise the file with [libraries]\n so vhdl_ls always has a valid minimal config.

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7. Inherit full process environment for the language server

ServerOptions.options.env in vscode-languageclient replaces the entire child process environment (Node.js child_process.spawn behaviour). The previous code only passed { VHDL_LS_CONFIG: "..." }, stripping PATH, HOME, TMPDIR, and every other OS-level variable from the vhdl_ls process.

Fix: spread process.env first so vhdl_ls inherits the full environment, with VHDL_LS_CONFIG overriding/adding on top.

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8. Fix duplicate forceRefresh causing unnecessary SIGKILL at startup

At startup, the teroshdl.vhdlls.restart command was being scheduled twice in quick succession:

1. Tree_view_manager constructor fires GLOBAL_REFRESH → refreshToml() → forceRefresh() → restart
2. init_tree_views() then also called forceRefresh() explicitly

Each restart call sends an LSP shutdown to the running vhdl_ls. If the server is busy (indexing files), it does not respond within the timeout and VS Code sends SIGKILL, then spawns a new instance. The double call meant two SIGKILLs back-to-back on startup.

Fix: remove the redundant explicit forceRefresh call in init_tree_views; the GLOBAL_REFRESH event from the Tree_view_manager constructor already handles it.

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9. Fix VSG formatter not applying edits to files with violations (all platforms)

This is a regression introduced in commit 63e925f. The formatter was changed to check exec_result.return_value === 0 for success, but the underlying local_process.ts always stores -1 in return_value for any non-zero exit — it was ignoring error.code from Node's ExecException.

VSG exits with:

• 0 — no violations found (file was already clean)
• 1 — violations found and fixed with --fix (the normal formatting outcome)

With return_value always being -1 for exit code 1, the success check return_value === 0 || return_value === 1 never matched exit code 1. successful was false, the edit was discarded, and the file appeared unchanged.

Only files that were already fully compliant (exit 0) ever got an edit applied, but all others did not.

Two-part fix:

• local_process.ts: store the actual exit code from error.code instead of always using -1. This is correct for all tools.
• vsg.ts: the existing return_value === 0 || return_value === 1 check now works as intended.

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Test plan

• Open a .vhd file on macOS Apple Silicon — VHDL LS starts without crashing
• "VHDL LS" Output channel shows all three config lines with no errors:
  • Loaded Installation configuration file: .../vhdl_libraries/vhdl_ls.toml
  • Loaded VHDL_LS_CONFIG configuration file: ...
  • Loaded workspace root configuration file: ... (if workspace has vhdl_ls.toml)
• Hover over a VHDL identifier — IEEE/STD type info appears
• Go-to-definition works for VHDL entities
• Open a .v/.sv file — no duplicate command activation error
• Format a VHDL file with VSG that has style violations — violations are fixed (not silently discarded)
• Format a VHDL file that is already compliant — no error, file unchanged
• On Linux/Windows — existing bundled binary paths and formatter behaviour unchanged