fix: vba-extractor — audit and fix VBA structural-recognition gaps from F.1 spike

[ardelperal]

Issue 4 — [P1] fix: vba-extractor — audit and fix VBA structural-recognition gaps from F.1 spike

Context

The F.1 spike report (docs/spikes/vbnet-as-vba.md, "VBA constructs the vbnet grammar fails on" section) identified 12 specific VBA constructs where the vbnet grammar fails to emit a dedicated node type. The full regex-based pipeline ALSO doesn't extract some of these directly — they fall back to heuristics or are not emitted.

The 12 gaps:

#	Construct	Current regex behavior	Fix or accept?
1	class_declaration / module_declaration wrapper	Heuristic (isCls ? kind='class' : kind='module' at vba-extractor.ts:281)	Accept (heuristic is fine for the bench corpus)
2	method_declaration / constructor_declaration / abstract_method_declaration	Extracted by PROC_RE in procedures.ts	Accept
3	field_declaration	Extracted by DIMS_RULES in dims.ts	Accept
4	property_declaration	Extracted via PROCEDURES_RULES (treating Property Get/Set/Let as procedures)	Accept
5	event_declaration / custom_event_declaration / raiseevent_statement	Partially handled by event-synth.ts	Audit (see below)
6	implements_clause	Handled by IMPLEMENTS_RULES	Accept
7	parameter_list / parameter	Handled inside procedures.ts signature parsing	Accept
8	const_declaration	BUG: Public Const X = Y is parsed as member_modifier (Public Const) + assignment_statement (X = Y) — the const nature is LOST	FIX (highest priority within this issue)
9	Wend loop terminator	Handled by pre-processing rewrite	Accept
10	VERSION 1.0 CLASS + BEGIN...END header	Handled by vba-extractor.ts:detectVbName	Accept
11	Attribute VB_* lines	Handled by stripVbaComments in vba-preprocess.ts	Accept
12	Option Compare Database / Option Explicit	Recognized as option_statement but position is wrong	Audit (see below)

Acceptance criteria

• Fix the Public Const bug (docs(readme): align header and add fork notes for codegraph-vba #8): emit a const symbol with kind: 'const', or tag the dim with metadata.isConst: true. Update enums-consts.ts:RULES to match ^\s*(?:Public|Private)\s+Const\s+\w+\s*= with a new emit body
• Audit gap fix(bin): allow Node 25 by default and silence banner in MCP mode #5 (event_declaration / raiseevent_statement): verify event-synth.ts correctly emits event-related edges for Public Event X(...) declarations and RaiseEvent X calls. If incomplete, document and fix
• Audit gap docs(all): align references and templates from .codegraph to .codegraph-vba #12 (Option statements): verify the regex layer's handling. If position-wrong, either accept (no real consequence) or fix
• Add regression test for the Public Const fix: a fixture with Public Const FOO As Long = 42 must emit a const symbol
• All 30 existing VBA tests still pass

Suggested approach

For the Public Const fix, add a rule to enums-consts.ts:

defineRule({
  id: 'module-const',
  description: 'Match `Public Const NAME = VALUE` or `Private Const NAME = VALUE`; emit a const symbol with kind:"const" so the const nature survives (vs. the dim-const rule which treats it as an assignment).',
  pattern: /^\s*(?:Public|Private)\s+Const\s+(\w+)\s*(?:As\s+(\w+))?\s*=\s*(.+?)\s*$/i,
  requires: 'module',
  emit: (m, ctx, line, lineNum) => {
    const name = m[1];
    const asType = m[2] ?? 'Variant';
    const value = m[3];
    ctx.nodes.push({
      id: generateNodeId(ctx.filePath, 'const', name, lineNum),
      kind: 'const',
      name,
      qualifiedName: name,
      filePath: ctx.filePath,
      language: 'vba',
      startLine: lineNum,
      endLine: lineNum,
      metadata: { value, asType, visibility: /Public/i.test(line) ? 'public' : 'private' },
    });
    return null;
  },
});

Place this rule BEFORE the dim-const rule in the table so the more specific pattern wins. Add a test fixture to __tests__/extraction-vba-realfixtures.test.ts.

Files touched

• src/extraction/vba/enums-consts.ts (new rule)
• __tests__/extraction-vba-realfixtures.test.ts (regression test)
• docs/spikes/vbnet-as-vba.md (note: 11 of 12 gaps accepted as-is; docs(readme): align header and add fork notes for codegraph-vba #8 fixed; fix(bin): allow Node 25 by default and silence banner in MCP mode #5 and docs(all): align references and templates from .codegraph to .codegraph-vba #12 audited)