🐛 fix(symbol): index all system tsf files

Do not drop system-library .tsf units when the file stem differs from top-level symbols.

Add test_provider support for --interpreter=... and an interpreter integration test that validates full indexing plus completion+resolve snippet.

lsp-server/src/manager/symbol.cppm

@@ -348,12 +348,10 @@ namespace lsp::manager
             auto stem = entry.path().stem().string();
             if (!HasMatchingTopLevelSymbol(*table, stem))
             {
-                spdlog::warn("Skipping system file {}: top-level symbol does not match file name (stem='{}', top-level={})",
-                             entry.path().string(),
-                             stem,
-                             DescribeTopLevelSymbols(*table));
-                ++failed;
-                continue;
+                spdlog::debug("Indexing system file {} with unmatched top-level symbol (stem='{}', top-level={})",
+                              entry.path().string(),
+                              stem,
+                              DescribeTopLevelSymbols(*table));
             }
 
             StoredSymbolEntry stored;