feat(python-scope): enumerate(X) for-loop tuple destructuring

Adds two new typeBinding capture patterns for the canonical enumerate
pattern:

  for (i, u) in enumerate(users): ...   ; tuple_pattern
  for  i, u  in enumerate(users): ...   ; pattern_list

Both bind the second tuple element (u) to the iterable identifier
(users). The chain-follow then unwraps users → its element type via
the existing generic-strip in interpret.ts (List[User] → User).

The #eq? predicate scopes the pattern to enumerate specifically;
generic tuple destructuring of arbitrary callables is left to a
future iteration once we have a richer signal for "what does this
call yield".

Verification:
- Flag-off: 191/191 (identical baseline).
- Flag-on: 7 fail / 184 pass (was 8/183; +1 — `parenthesized tuple:
  for (i, u) in enumerate(users)` now passes).
- tsc --noEmit clean.

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

@@ -119,6 +119,31 @@ export const PYTHON_SCOPE_QUERY = `
   right: (call
     function: (identifier) @type-binding.type)) @type-binding.alias
 
+;; for (i, u) in enumerate(X) — paren-tuple, bind last element to X's
+;; element type. \`enumerate(X)\` yields (int, X-element); the second
+;; pattern var takes X (which the chain-follow then unwraps to its
+;; element type via generic-strip in interpret.ts).
+(for_statement
+  left: (tuple_pattern
+    (identifier)
+    (identifier) @type-binding.name)
+  right: (call
+    function: (identifier) @_enum
+    arguments: (argument_list
+      (identifier) @type-binding.type))
+  (#eq? @_enum "enumerate")) @type-binding.alias
+
+;; for i, u in enumerate(X) — pattern_list (no parens) variant.
+(for_statement
+  left: (pattern_list
+    (identifier)
+    (identifier) @type-binding.name)
+  right: (call
+    function: (identifier) @_enum
+    arguments: (argument_list
+      (identifier) @type-binding.type))
+  (#eq? @_enum "enumerate")) @type-binding.alias
+
 ;; Type bindings (variable annotations: \`u: User\` / \`u: User = x\`)
 (assignment
   left: (identifier) @type-binding.name

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

@@ -134,6 +134,30 @@
   right: (call
     function: (identifier) @type-binding.type)) @type-binding.alias
 
+; for (i, u) in enumerate(X) and for i, u in enumerate(X) — bind the
+; second tuple element to X. enumerate yields (int, X-element); the
+; chain-follow unwraps X via generic-strip when X is an annotated
+; collection.
+(for_statement
+  left: (tuple_pattern
+    (identifier)
+    (identifier) @type-binding.name)
+  right: (call
+    function: (identifier) @_enum
+    arguments: (argument_list
+      (identifier) @type-binding.type))
+  (#eq? @_enum "enumerate")) @type-binding.alias
+
+(for_statement
+  left: (pattern_list
+    (identifier)
+    (identifier) @type-binding.name)
+  right: (call
+    function: (identifier) @_enum
+    arguments: (argument_list
+      (identifier) @type-binding.type))
+  (#eq? @_enum "enumerate")) @type-binding.alias
+
 ; ─── Type bindings: function return-type annotations ─────────────────────
 ;
 ; `def get_user() -> User:` — binds the function's NAME to its return