feat: add BSL (1C Enterprise) language support

[Alex1980Alex]

Closes #147.

Adds a multilspy adapter for the BSL Language Server (https://github.com/1c-syntax/bsl-language-server), pinned to 0.22.0.

Changes

• `Language.BSL = "bsl"` in multilspy_config.py.
• Factory registration in language_server.py.
• New package language_servers/bsl_language_server/:
  • bsl_language_server.py — LanguageServer subclass that launches java -jar bsl-language-server.jar --lsp (argv-list form for cross-platform subprocess.exec; Windows does not accept a shell-style command string).
  • runtime_dependencies.json — pins BSL LS 0.22.0 with SHA256 (verified after download).
  • initialize_params.json — BSL-specific capabilities.
• Three integration tests in tests/multilspy/test_multilspy_bsl.py (document_symbols, references, rename), skipped if java not in PATH.
• .gitignore excludes bsl_language_server/static/ like other JAR-based adapters.
• README.md lists BSL in supported languages.

Why a separate ProcessLaunchInfo shape

ProcessLaunchInfo.cmd is List[str] per the dataclass definition. A single shell-style string (used in some third-party adapters) breaks Windows asyncio.create_subprocess_exec. The BSL adapter always passes an argv list.

Local verification

```
$ java -version
openjdk version "17.0.13" 2024-10-15 LTS
OpenJDK Runtime Environment Zulu17.54+21-CA (build 17.0.13+11-LTS)

$ python -m pytest tests/multilspy/test_multilspy_bsl.py -v
tests/multilspy/test_multilspy_bsl.py::test_multilspy_bsl_start_and_document_symbols PASSED
tests/multilspy/test_multilspy_bsl.py::test_multilspy_bsl_references_in_same_module PASSED
tests/multilspy/test_multilspy_bsl.py::test_multilspy_bsl_rename_returns_workspace_edit PASSED
============= 3 passed in 24.15s =============
```

Platform: Windows 11, Python 3.13.1.

Prerequisites

• Java 17+ in PATH.
• First run downloads ~94 MB JAR from https://github.com/1c-syntax/bsl-language-server/releases/download/0.22.0/bsl-language-server-0.22.0.jar (SHA256 validated before use).

Diff size

9 files, +387 / −2 lines, 2 commits:

• `e985819` — feat: add BSL (1C Enterprise) language support
• `f2a5702` — fix(bsl): verify SHA256 after JAR download + log shutdown errors

Happy to address review comments within 48h.

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[LakshyAAAgrawal]

Thanks for this well-structured PR, @Alex1980Alex! The SHA256 verification on the JAR download is a nice touch, and the overall code quality is solid. A few things to address before we can merge:

1. Download URL returns 404 — The JAR at https://github.com/1c-syntax/bsl-language-server/releases/download/0.22.0/bsl-language-server-0.22.0.jar is returning 404 in CI. Could you verify the correct release URL? The release may have been renamed or removed upstream.

2. Install directory — The JAR is currently downloaded to os.path.dirname(file) + "/static/", which writes into the Python package's site-packages directory. We moved all servers to use ~/.multilspy/lsp/<server_name>/ in Move LSP installs to ~/.multilspy/lsp/, add server_binary and server_install_dir config #137. Please change to:

   from multilspy.multilspy_settings import MultilspySettings

   server_dir = config.server_install_dir or MultilspySettings.get_server_install_directory("bsl-language-server")

3. server_binary support — All servers now check config.server_binary at the top of their setup method to let users point to a pre-installed binary. Please add:

   if config.server_binary:
   assert os.path.exists(config.server_binary), f"Server binary not found: {config.server_binary}"
   return ["java", "-jar", config.server_binary, "--lsp"]

4. Missing trailing newline in .gitignore — both the old and new last lines lack a newline at EOF.

5. The method name _ensure_jar could be setup_runtime_dependencies for consistency with other servers.

6. The rename test calls lsp.server.send.rename() directly, which is the internal protocol handler rather than the multilspy public API. This is fine for now since rename isn't exposed as a public method yet, but worth noting.

Happy to help if you have questions about any of these. The overall implementation looks great — looking forward to getting this in!