Adds the brainstormed design for landing deep Dart support at parity with
the recent Kotlin add (PR Egonex-AI#347): LanguageConfig + tree-sitter WASM grammar
(tree-sitter-dart@1.0.0, verified ships a prebuilt .wasm in its tarball) +
DartExtractor + ~22 vitest cases. Six file changes, no edits to shared
schemas/registries.
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

Live verification during planning surfaced two facts that change the
shipping strategy:
1. tree-sitter-dart@1.0.0's prebuilt wasm uses the pre-`dylink.0` format
 and fails to load in web-tree-sitter@0.26.x (the version this project
 uses). Verified by directly loading the upstream wasm and catching
 the failure in getDylinkMetadata.
2. The grammar source itself is sound — rebuilding with the current
 tree-sitter-cli@0.26.x + wasi-sdk-29 toolchain produces a working
 dylink.0-format wasm that parses every construct the extractor needs.
Revised packaging: ship the freshly-built wasm as a workspace-internal
package (@understand-anything/tree-sitter-dart-wasm) rather than
depending on the broken upstream npm artifact. No loader changes
required; existing TreeSitterPlugin resolves it the same way it
resolves other tree-sitter packages.
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

Thirteen-task TDD plan walking from vendoring the workspace wasm package
through scaffolding the extractor and adding extraction logic in
test-first slices: functions, classes, constructors, mixins, extensions,
enums, imports, exports, visibility, and call graph.
Every code block reflects AST shapes confirmed via a live probe against
a freshly-built tree-sitter-dart wasm in the project's own
web-tree-sitter at 0.26.x. No placeholder code, no "fill in later"
references.
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

The upstream tree-sitter-dart@1.0.0 ships a pre-`dylink.0` wasm that
fails to load in web-tree-sitter@0.26.x. The grammar source itself is
sound — rebuilding with the current tree-sitter-cli + wasi-sdk produces
a working dylink.0 wasm. Vendor that artifact as a workspace-internal
package so @understand-anything/core can depend on it via workspace:*.
BUILD.md documents the provenance and rebuild instructions.

Adds the Dart language config and wires it into builtinLanguageConfigs
so .dart files are recognized by the language registry. References the
vendored @understand-anything/tree-sitter-dart-wasm package for grammar
loading.
No extractor yet — structural extraction lands in the next commit.

Empty extractor that satisfies the LanguageExtractor interface so the
plugin pipeline can load it. Real extraction logic lands in subsequent
TDD commits.

Add TDD tests and implement extractTopLevelFunction with helpers for
extracting function name, params, and return type (including generics
where the grammar emits type_identifier + type_arguments as siblings).
Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

Add constructorName() helper and extend collectClassBody() to surface
unnamed constructors as "ClassName", named constructors as "Class.named",
and factory named constructors as "Class.named" in methods[]/functions[].
Probe confirmed plan's AST shapes match exactly; extractReturnType returns
undefined for all constructor forms (factory keyword is an unnamed node).
Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

Add mixin_declaration handling to extractStructure, folding mixins into
classes[] (same convention as class_definition). The `on` constraint
sibling is intentionally ignored for graph purposes.
Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

Adds enum_declaration handling to DartExtractor: enum constants are surfaced
as properties[] so the structural graph captures Color.red / Color.green etc.
Implements Task 9 of the Dart language support plan (TDD, 16/16 dart tests
pass, full suite 708/708).
Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

...as) + export directives
Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

Implements extractCallGraph with a sibling-aware walk that pairs each
function_signature with its subsequent function_body sibling (Dart's
AST differs from Kotlin's: signature and body are siblings, not
parent/child). Detects call sites via selector nodes containing
argument_part; uses startIndex for sibling lookup (web-tree-sitter
returns new wrapper objects per child() call, making === unreliable).
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

Per maintainer feedback on Egonex-AI#436 — these are personal brainstorm/plan
artifacts produced via the superpowers skill flow, not repo
documentation. The BUILD.md provenance note in
packages/tree-sitter-dart-wasm/ stays since that's repo-level docs
about the vendored wasm.

Incorporates stronger pieces from the prior Dart attempts (Egonex-AI#348, Egonex-AI#415)
that @Lum1104 called out:
- `extractParams` now walks `optional_formal_parameters` (covers both
 optional positional `[...]` AND named `{...}` parameters — the Dart
 grammar uses one wrapper for both).
- New `extractParamName` helper extracts the user-visible field name
 from `this.field` and `super.field` initializer parameters by
 unwrapping `constructor_param` / `super_formal_parameter`.
- `collectClassBody` now routes `getter_signature` and `setter_signature`
 in both shapes:
 - concrete: `method_signature > getter_signature` + sibling function_body
 - abstract: `declaration > getter_signature`
 Setters use the same path. The previous limitation assertion
 (`methods).not.toContain("value")`) flipped to a positive
 `.toContain("value")`.
- Added import/export edge-case tests: `dart:` SDK URIs, multi-import
 declaration-order preservation, and `export ... show` clauses.
- Added a comma-list field test (`int a, b, c;`).
Underscore-prefix visibility carries through naturally to all new code
paths via the existing `isExported` gate inside `pushMethod`; explicit
test added for an underscore-prefixed getter.
Test counts: 28 → 41 dart cases; full core suite 720 → 733; no
regressions.