feat(python): capture constructor-inferred + annotated type bindings

Extends the Python scope-extractor with two new type-binding capture
patterns so receiver-typed method dispatch has concrete type bindings
to work from:

1. `u: User = ...` / `u: User` — variable annotations. `@type-binding.annotation`
   anchor, `source: 'annotation'`.
2. `u = User("alice")` — assignment RHS is a bare-identifier call (Python
   has no `new` keyword; constructor-shaped calls are syntactically
   identical to function calls). `@type-binding.constructor` anchor,
   `source: 'constructor-inferred'`.

The runtime query lives in `query.ts` (the `.scm` file is documentation
per the comment at its top); both are updated.

Fixes 19 failures across these resolver fixtures (flag-on 82 → 63):
- Python constructor-inferred type resolution (3)
- Python class-level annotation resolution (3)
- Python nullable receiver resolution (3)
- Python member-call / receiver-constrained / constructor-call (3)
- Python assignment chain propagation (2)
- Python walrus / match-case / chained method (3)
- Python member access iterable for-loop (2)

gitnexus/src/core/ingestion/languages/python/interpret.ts

@@ -11,12 +11,7 @@
  * already attached) so these functions are straight-line tag readers.
  */
 
-import type {
-  CaptureMatch,
-  ParsedImport,
-  ParsedTypeBinding,
-  TypeRef,
-} from 'gitnexus-shared';
+import type { CaptureMatch, ParsedImport, ParsedTypeBinding, TypeRef } from 'gitnexus-shared';
 
 // ─── interpretImport ──────────────────────────────────────────────────────
 
@@ -108,11 +103,19 @@ export function interpretPythonTypeBinding(captures: CaptureMatch): ParsedTypeBi
   // `def f(x: "User")`.
   const rawType = stripForwardRefQuotes(typeCap.text.trim());
 
+  // Order matters: more specific anchor captures take precedence. `self`
+  // and `cls` are synthesized with their own marker captures; the SCM
+  // anchor topic captures (`@type-binding.parameter`,
+  // `@type-binding.annotation`, `@type-binding.constructor`) distinguish
+  // the variable-annotation and constructor-inferred forms from the
+  // classic parameter annotation.
   let source: TypeRef['source'] = 'parameter-annotation';
   if (captures['@type-binding.self'] !== undefined) source = 'self';
   // `cls` is a self-like receiver; share the source label so downstream
   // `Registry.lookup` Step 2 treats them identically.
   else if (captures['@type-binding.cls'] !== undefined) source = 'self';
+  else if (captures['@type-binding.constructor'] !== undefined) source = 'constructor-inferred';
+  else if (captures['@type-binding.annotation'] !== undefined) source = 'annotation';
 
   return { boundName: nameCap.text, rawTypeName: rawType, source };
 }

gitnexus/src/core/ingestion/languages/python/query.ts

@@ -48,6 +48,17 @@ export const PYTHON_SCOPE_QUERY = `
   name: (identifier) @type-binding.name
   type: (type) @type-binding.type) @type-binding.parameter
 
+;; Type bindings (variable annotations: \`u: User\` / \`u: User = x\`)
+(assignment
+  left: (identifier) @type-binding.name
+  type: (type) @type-binding.type) @type-binding.annotation
+
+;; Type bindings (constructor-inferred: \`u = User(...)\`)
+(assignment
+  left: (identifier) @type-binding.name
+  right: (call
+    function: (identifier) @type-binding.type)) @type-binding.constructor
+
 ;; References — calls
 (call
   function: (identifier) @reference.name) @reference.call.free
@@ -71,10 +82,7 @@ export function getPythonParser(): Parser {
 
 export function getPythonScopeQuery(): Parser.Query {
   if (_query === null) {
-    _query = new Parser.Query(
-      Python as Parameters<Parser['setLanguage']>[0],
-      PYTHON_SCOPE_QUERY,
-    );
+    _query = new Parser.Query(Python as Parameters<Parser['setLanguage']>[0], PYTHON_SCOPE_QUERY);
   }
   return _query;
 }

gitnexus/src/core/ingestion/languages/python/scopes.scm

@@ -91,6 +91,36 @@
   name: (identifier) @type-binding.name
   type: (type) @type-binding.type) @type-binding.parameter
 
+; ─── Type bindings: variable annotations ───────────────────────────────────
+;
+; `u: User` or `u: User = some_value` — `u` is explicitly annotated. Both
+; forms parse under tree-sitter-python as `(assignment left: type:)` with
+; an optional `right:`. Module-, class-, and function-scope annotations
+; all land here; scope attachment is handled by the central extractor
+; via the anchor's innermost-containing scope.
+;
+; Emits `source: 'annotation'`.
+
+(assignment
+  left: (identifier) @type-binding.name
+  type: (type) @type-binding.type) @type-binding.annotation
+
+; ─── Type bindings: constructor-inferred assignments ───────────────────────
+;
+; `u = User("alice")` — `u`'s type is inferred from the RHS call's target.
+; Python has no `new` keyword, so the pattern matches any `assignment`
+; whose RHS is a `call` with a bare-identifier function (constructor-
+; shaped). The registry resolves the raw name through the scope chain at
+; lookup time, so imported classes, local classes, and aliased imports
+; all work without query-time knowledge.
+;
+; Emits `source: 'constructor-inferred'`.
+
+(assignment
+  left: (identifier) @type-binding.name
+  right: (call
+    function: (identifier) @type-binding.type)) @type-binding.constructor
+
 ; ─── References: calls ─────────────────────────────────────────────────────
 ;
 ; Free call:   `print(x)`     — function is a bare identifier