feat: complete BLOCK_LIST/ADDR_LIST keywords and space comments

Add keyword-driven completions for BLOCK_LIST and ADDR_LIST in the LSP server.
- While typing a prefix of these keywords the server returns the keyword(s)
  as incomplete snippet suggestions that trigger a re-request.
- Once the keyword is typed the server replaces it with a full list of the
  corresponding loaded block templates or addresses (quoted), and sets each
  item's filter_text to include the keyword so further typing narrows results.
- Integrate this flow into on_completion and factor the symbol-list logic
  into a helper that returns either incomplete keyword suggestions or the
  completed symbol list.

Also implement NxFormatter.format_comment to ensure a single space after a
leading '#' for comments that don't already start with whitespace, while
leaving sequences of '#' (separators), shebangs, and already-spaced comments
unchanged. This affects both standalone and inline comments.

Add/rename tests to cover the new completions and comment-spacing behavior.

server/tests/python_tests/test_def_symbols.py

@@ -198,3 +198,63 @@ def test_typed_quotes_are_replaced_not_doubled(tmp_path, monkeypatch):
         )
     ).items
     assert _edit(items, "SPOS") == ('"SPOS"', (22, 26))
+
+
+def test_block_list_prefix_offers_keyword_and_stays_incomplete(tmp_path, monkeypatch):
+    server, _ = _project(tmp_path, monkeypatch)
+    uri = (tmp_path / "caller.tcl").as_uri()
+    source = "MOM_do_template BLOCK_L"
+    server.workspace.put_text_document(
+        lsp.TextDocumentItem(uri=uri, language_id="tcl", version=next(_versions), text=source)
+    )
+    result = lsp_server.on_completion(
+        lsp.CompletionParams(
+            text_document=lsp.TextDocumentIdentifier(uri=uri),
+            position=lsp.Position(line=0, character=len(source)),
+        )
+    )
+    assert result.is_incomplete
+    keyword = result.items[0]
+    assert keyword.label == "BLOCK_LIST"
+    assert keyword.command.command == "editor.action.triggerSuggest"
+
+
+def test_block_list_shows_all_templates_quoted(tmp_path, monkeypatch):
+    server, _ = _project(tmp_path, monkeypatch)
+    items = _complete(server, tmp_path, "set a 1\n    BLOCK_LIST")
+    assert [item.label for item in items] == ["external_subprogram", "steady_rest"]
+    assert _edit(items, "steady_rest") == ('"steady_rest"', (4, 14))
+    assert all(item.filter_text.startswith("BLOCK_LIST") for item in items)
+
+
+def test_block_list_ignores_variables_and_other_words(tmp_path, monkeypatch):
+    server, _ = _project(tmp_path, monkeypatch)
+    for source in ("set x $BLOCK_LIST", "set x MY_BLOCK_LIST", "set x steady"):
+        labels = [item.label for item in _complete(server, tmp_path, source)]
+        assert "BLOCK_LIST" not in labels
+
+
+def test_addr_list_shows_all_addresses_quoted(tmp_path, monkeypatch):
+    server, _ = _project(tmp_path, monkeypatch)
+    items = _complete(server, tmp_path, "MOM_force Once ADDR_LIST")
+    assert [item.label for item in items] == ["SPOS", "X"]
+    assert _edit(items, "SPOS") == ('"SPOS"', (15, 24))
+    assert all(item.filter_text.startswith("ADDR_LIST") for item in items)
+
+
+def test_addr_list_prefix_offers_keyword(tmp_path, monkeypatch):
+    server, _ = _project(tmp_path, monkeypatch)
+    uri = (tmp_path / "caller.tcl").as_uri()
+    source = "ADDR"
+    server.workspace.put_text_document(
+        lsp.TextDocumentItem(uri=uri, language_id="tcl", version=next(_versions), text=source)
+    )
+    result = lsp_server.on_completion(
+        lsp.CompletionParams(
+            text_document=lsp.TextDocumentIdentifier(uri=uri),
+            position=lsp.Position(line=0, character=len(source)),
+        )
+    )
+    assert result.is_incomplete
+    assert result.items[0].label == "ADDR_LIST"
+    assert "BLOCK_LIST" not in {item.label for item in result.items}

server/tests/python_tests/test_formatter.py

@@ -1,4 +1,4 @@
-"""Formatting of uplevel bodies."""
+"""Formatting with NxFormatter."""
 
 from tclint.format import FormatterOpts
 from tools.formatter import NxFormatter
@@ -31,3 +31,28 @@ def test_uplevel_without_level_and_with_variable_level():
     assert _format(source) == (
         "uplevel {\n\tset x 1\n}\nuplevel $lvl {\n\tset y 2\n}\nuplevel set z 3\n"
     )
+
+
+def test_comment_gets_space_after_hash():
+    source = (
+        "#Comment\n"
+        "# already spaced\n"
+        "#\tTabbed\n"
+        "#\n"
+        "##########\n"
+        "set x 1 ;#inline\n"
+        "proc a {} {\n"
+        "\t#nested\n"
+        "}\n"
+    )
+    assert _format(source) == (
+        "# Comment\n"
+        "# already spaced\n"
+        "#\tTabbed\n"
+        "#\n"
+        "##########\n"
+        "set x 1 ;# inline\n"
+        "proc a {} {\n"
+        "\t# nested\n"
+        "}\n"
+    )