feat(objectscript): InterSystems IRIS ObjectScript language support

[isc-tdyar]

What does this PR do?

Adds ObjectScript (InterSystems IRIS / Caché) as a supported language, per the discussion in #462.

ObjectScript powers large healthcare, finance, and enterprise systems and has no support in CBM (or most code-graph tools). This PR makes those codebases indexable and resolves the call-dispatch patterns that are structurally invisible to text search.

Refs #462

⚠️ Read first — grammar is a separate dependency

Per your note on #462, this PR contains only the CBM source changes — not the vendored grammar. The two tree-sitter grammars come from intersystems/tree-sitter-objectscript (MIT licensed, maintained by the language vendor): objectscript_udl (.cls) and objectscript_routine (.mac/.inc/.rtn/.int).

Consequence: the build will not link until the grammar is vendored at internal/cbm/vendored/grammars/objectscript_udl/ and …/objectscript_routine/ — it fails on the missing tree_sitter_objectscript_udl() / _routine() symbols. CI will be red until then. That is intentional, matching your plan to audit and vendor the grammar independently. The grammar shims (grammar_objectscript_*.c) that declare those factories are included — only the generated parser.c/scanner.c are omitted.

What's in the PR

Definition extraction — Class, Method, ClassMethod, Property, Parameter, Index, Trigger (with body text), XData, Storage, Query members → graph nodes; base classes from the Extends clause.

Four call-dispatch patterns (all resolved statically at index time):

Pattern	Example	Notes
Explicit cross-class	##class(Pkg.Class).Method()	from AST
Relative-dot self-call	..Method()	the dominant intra-class form; large impact on CALLS completeness
Macro expansion	$$$Macro	resolved via a per-project table built from .inc files
Type inference	Set x = ##class(P).%New() … x.Save()	from %New/%OpenId + declared return types

Ensemble production topology (pass_ensemble_routing.c) — EnsembleItem nodes per production component and ROUTES_TO edges resolved from ProductionDefinition XData; plus WorkMgr .Queue("##class(X).method") dispatch. All static — no live IRIS instance required.

Two design points for your review

1. Public API unchanged. ObjectScript needs two per-project tables (a $$$macro table and a method-return-type table) that single-file extraction can't build alone. Rather than widen the public cbm_extract_file() signature (which would ripple NULL, NULL through every call site), I added an internal cbm_extract_file_ex() that carries the tables; cbm_extract_file() is a thin wrapper that delegates with NULL, NULL. Only the pipeline passes that build the tables call _ex.

2. Extension collisions with Apex and BitBake (both added since I started this work). .mac/.int/.rtn map to ObjectScript routine directly. The two collisions are resolved by content sniffing, following the existing cbm_disambiguate_m() (.m MATLAB-vs-ObjC) pattern, and default to the existing language on any doubt so neither Apex nor BitBake regresses:

   • .cls (vs Apex): a Class <Uppercase…> header line → ObjectScript UDL, else Apex. Edge case: a .cls whose Class line sits beyond the first 4 KB (e.g. a very large license banner) would fall through to Apex.
   • .inc (vs BitBake): a ROUTINE <Uppercase> header or an ObjectScript preprocessor directive (#define / #def1arg / #;) → ObjectScript routine, else BitBake. (#define/#def1arg never collide with BitBake, which uses # only for # comment.)

   These are the spots most likely to need your input — happy to adjust the heuristics or the generalization however you prefer.

EnsembleItem label (your Q2 on #462)

I used a domain-specific EnsembleItem node label and ROUTES_TO edge type. If you'd prefer a generic label (ServiceComponent / WorkflowNode) with ensemble_item as a property, I'm glad to rename — just let me know before merge.

Tests

tests/test_extraction.c gains the ObjectScript suite: UDL class/method extraction, all four dispatch patterns, Ensemble topology parsing, macro expansion, trigger body text, and Export-XML transcoding. The Export-XML transcoder tests are grammar-independent and pass today; the grammar-dependent tests pass once the grammar is vendored. No other test files are touched.

Scope / roadmap

This PR is the foundation. If it's well received, two separate follow-up PRs would complete the story (each with its own issue): (a) cross-version version_tag + diff_versions, and (b) ObjectScript-tuned semantic embeddings. They're deliberately excluded here to keep this reviewable.

Checklist

• Every commit is signed off (git commit -s) — DCO
• Tests pass locally (make -f Makefile.cbm test) — passes once the grammar is vendored; see note above
• Lint passes (make -f Makefile.cbm lint-ci)
• New behavior is covered by tests