feat(pascal): add Pascal language server support

Add support for Free Pascal/Lazarus projects using pasls.

Features:
- Auto-download pasls binary for Linux, macOS, and Windows
- Platform detection for x64 and arm64 architectures
- Support for FPC environment variables (PP, FPCDIR)

CI: Add FPC compiler installation (fpc-ootb for Windows)

Includes test repository and unit tests.

test/solidlsp/pascal/__init__.py

@@ -0,0 +1,15 @@
+def _check_pascal_available() -> bool:
+    """Check if Pascal language server (pasls) is available.
+
+    Note: pasls will be auto-downloaded if not present, so Pascal
+    support is always available.
+    """
+    return True
+
+
+PASCAL_AVAILABLE = _check_pascal_available()
+
+
+def is_pascal_available() -> bool:
+    """Return True if Pascal language server can be used."""
+    return PASCAL_AVAILABLE