feat(extraction): add Visual Basic .NET language support (.vb) (#648, #639, #170) (#1164)

Vendored patched govindbanura/tree-sitter-vbnet grammar (MIT, ~20-fix patch
+ new external scanner for XML literals and multi-line LINQ continuation;
provenance + rebuild instructions in docs/grammars/tree-sitter-vbnet.md),
vbnet extractor with VB-specific call/index disambiguation, Inherits/
Implements heritage, As New instantiation, events, Declare P/Invoke, and
MustOverride abstract members.

Parse health on five real repos: PolicyPlus 100%, CompactGUI 100%,
staxrip 95.2%, SCrawler 87.2%, PCL 87.5% (upstream grammar: 3-18%).
Retrieval A/B (sonnet): 26-43% faster with 0-5 file reads vs 7-20 without.

Co-authored-by: Claude Fable 5 <noreply@anthropic.com>

CHANGELOG.md

@@ -11,6 +11,7 @@ and adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0.html).
 
 ### New Features
 
+- CodeGraph now indexes **Visual Basic .NET** (`.vb`) — classes, Modules, interfaces, structures, enums, properties, events, `MustOverride` abstract members, and `Declare` P/Invoke signatures, with `Inherits`/`Implements` hierarchy edges, call edges (resolved through VB's ambiguous call-vs-index parentheses), and `New`/`As New` instantiation links. Real-world VB styles parse cleanly: WinForms designer files, interpolated and multi-line strings, XML literals (embedded `<%= %>` expressions included), single-line and multi-line LINQ queries, multi-line lambdas, `Handles`/`WithEvents` event wiring, Custom Events, date literals, classic type-character identifiers (`i%`, `name$`), and non-English (Unicode) identifiers. (#648, #639, #170)
 - CodeGraph now indexes **COBOL** (`.cbl`, `.cob`, `.cpy`) — programs, sections and paragraphs with `PERFORM`/`GO TO` call edges, `CALL` cross-program calls, `COPY` copybook imports (standalone copybooks included), and DATA DIVISION records with 88-level condition names, in both fixed and free source format. Impact queries work on data items: every `MOVE`/`ADD`/`COMPUTE`/`SUBTRACT` write-site links back to the field it changes, so "what touches this copybook field" answers across programs. CICS flows connect too: `EXEC CICS LINK`/`XCTL` program targets, `EXEC SQL INCLUDE` copybooks, and pseudo-conversational `RETURN TRANSID(...)` hops resolve to the program owning the transaction id. (#590, #648)
 - CodeGraph now indexes **CFML** (`.cfc`, `.cfm`, `.cfs`) — both the classic tag-based style (`<cfcomponent>`/`<cffunction>`) and modern bare-script `component { ... }` syntax, including `extends`/`implements`, embedded `<cfscript>` blocks (at any nesting depth, including inside `<cfif>`/`<cfloop>`/`<cftry>`), call edges, and calls embedded in `#hash#` expressions inside `<cfquery>` SQL bodies. Files saved with a UTF-8 byte-order mark and tags with unquoted attribute values — both common in long-lived CFML codebases — are handled too. Thanks @ghedwards. (#1118)
 - CFML inheritance written as a component path now links to the right component. `extends="coldbox.system.web.Controller"` names its supertype by dotted path and `extends="../base"` by relative path (the FW/1 style) — both previously produced no inheritance edge at all, which on framework-style CFML apps hid most of the type hierarchy from impact and blast-radius analysis (on ColdBox's own core, over 90% of inheritance was invisible). Resolution is deliberately conservative: the target's directory layout must corroborate the declared path — so a supertype that lives in an out-of-repo library (testbox, mxunit, an installed framework) correctly stays unlinked rather than being guessed at, and an ambiguous path produces no edge rather than a wrong one. (#1152)