feat(solidlsp): add Astro language server support (#2085)

* feat(solidlsp): add Astro language server support (T170)

* test(solidlsp): fix relative_paths type extraction in test_astro_basic

* refactor(solidlsp): replace asserts with explicit exceptions in Astro LSP

* docs(memories): document rule against assert in language server guide

* docs: add Astro language server documentation (README, docs, template, CHANGELOG)

* feat(solidlsp): implement dual-server architecture for Astro with companion TypeScript server (#2085)

- Implement companion AstroTypeScriptServer using @astrojs/ts-plugin for cross-file code intelligence between .ts and .astro components
- Route .ts/.js document symbols, definitions, references, and renames through companion TypeScript server
- Support two-way buffer edit forwarding between Astro LS and companion TS server
- Replace all assert statements with explicit SolidLSPException and FileNotFoundError
- Handle *.customData configuration requests for Volar HTML service
- Register .astro extension in src/serena/hooks.py
- Add test fixtures and tests for symbol retrieval and cross-file references from TypeScript to Astro components
- Update documentation and CHANGELOG

* fix(solidlsp): narrow astro_ls type to AstroLanguageServer in companion server test

* fix(solidlsp): prevent caching empty document symbols and poll initial compilation in Nextflow tests

test/solidlsp/astro/conftest.py

@@ -0,0 +1,69 @@
+"""
+Pytest fixtures for Astro language server tests.
+
+This conftest does NOT install the language server itself -- that is handled by
+``RuntimeDependencyCollection`` inside ``AstroLanguageServer`` and lands in Serena's
+managed ``ls_resources_dir`` like every other LS download.
+
+What we install here is the test fixture project's npm dependencies (notably
+``astro``) into the fixture's own ``node_modules``. The companion tsserver (via
+``@astrojs/ts-plugin``) needs ``astro`` resolvable from the workspace to understand
+``.astro`` modules; without it, cross-file references between ``.ts`` and ``.astro``
+files return nothing and the tests would pass vacuously.
+"""
+
+from __future__ import annotations
+
+import logging
+import os
+import shutil
+import subprocess
+from pathlib import Path
+
+import pytest
+from filelock import FileLock
+
+log = logging.getLogger(__name__)
+
+REPO_ROOT = Path(__file__).resolve().parents[2] / "resources" / "repos" / "astro" / "test_repo"
+NODE_MODULES = REPO_ROOT / "node_modules"
+ASTRO_MARKER = NODE_MODULES / "astro" / "package.json"
+INSTALL_LOCK = REPO_ROOT / ".astro-install.lock"
+
+
+@pytest.fixture(scope="session", autouse=True)
+def _install_astro_test_repo_node_modules() -> None:
+    """Populate the Astro fixture's project dependencies via npm (cached across sessions)."""
+    if ASTRO_MARKER.exists():
+        log.info("Astro test repo node_modules already populated; skipping npm install")
+        return
+
+    npm_executable = shutil.which("npm.cmd") or shutil.which("npm")
+    if npm_executable is None:
+        pytest.skip("npm is not available; cannot install Astro test repo dependencies")
+
+    with FileLock(str(INSTALL_LOCK)):
+        if ASTRO_MARKER.exists():
+            log.info("Astro test repo node_modules populated by another worker; skipping npm install")
+            return
+
+        log.warning(
+            "Installing npm dependencies into the Astro test repo at %s. This is a one-time cost per checkout.",
+            REPO_ROOT,
+        )
+        proc = subprocess.run(
+            [npm_executable, "install", "--no-audit", "--no-fund", "--loglevel=warn"],
+            cwd=str(REPO_ROOT),
+            capture_output=True,
+            text=True,
+            check=False,
+            env=os.environ.copy(),
+        )
+        if proc.returncode != 0:
+            log.error("npm install failed (rc=%s).\nstdout:\n%s\nstderr:\n%s", proc.returncode, proc.stdout, proc.stderr)
+            pytest.skip(f"npm install failed in {REPO_ROOT} (rc={proc.returncode}); see logs for details")
+
+        if not ASTRO_MARKER.exists():
+            pytest.skip(f"npm install completed but {ASTRO_MARKER} is missing; cannot run Astro tests")
+
+        log.info("Astro test repo node_modules installed successfully")