docs: add Swift ingestion gaps tracker and update feature matrix

- Create swift-ingestion-gaps.md with prioritized gap tracker (High/Medium/Low)
- Update type-resolution-system.md feature matrix: 5 Swift entries corrected
  (for-loop→Yes, pattern binding→Partial, call-result/field/method→Yes)
- Add footnotes explaining Swift-specific semantics
- Document resolved items with commit references

Addresses @magyargergo's request to document missing Swift features.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

swift-ingestion-gaps.md

@@ -0,0 +1,79 @@
+# Swift Ingestion Gaps
+
+Tracks missing Swift features in the GitNexus ingestion pipeline. Organized by priority.
+
+## 🔴 High Priority
+
+### Type Inference
+
+| Gap | Description | Impact |
+|-----|-------------|--------|
+| `if let` / `guard let` inside for-loop bodies | Type-env binds the variable correctly but call-processor's re-parse path doesn't propagate for-loop element bindings to receiver resolution | Calls inside `for item in collection` are unresolved |
+| `while let` binding | `while let x = iter.next()` not in `DECLARATION_NODE_TYPES` | Uncommon but valid Swift pattern |
+
+### Call Resolution
+
+| Gap | Description | Impact |
+|-----|-------------|--------|
+| `await expr` / `try expr` as call wrappers | `await_expression` and `try_expression` wrap `call_expression` — call extraction queries match but the outer wrapper can interfere with receiver resolution in some paths | Most cases work via `unwrapSwiftExpression` but edge cases remain |
+| Multi-hop chains | `a.b.c()` — only single-hop `receiver.method()` resolved | Common in UIKit/SwiftUI code |
+| Trailing closures | `items.map { $0.save() }` — `$0` type not inferrable | Functional-style Swift code |
+
+## 🟡 Medium Priority
+
+### Symbol Extraction
+
+| Gap | Description | Impact |
+|-----|-------------|--------|
+| Enum `case` as callable | `MyEnum.case` calls are member-form, not caught by constructor fallback | Enum-heavy code (Result, State enums) |
+| Subscript declarations | `subscript(i:) -> T` not captured | Protocol conformance tracking |
+| Operator overloads | `static func + (lhs:, rhs:)` not captured | Mathematical types |
+| `deinit` | `deinit {}` not captured | Minor — rarely called explicitly |
+
+### Heritage / Inheritance
+
+| Gap | Description | Impact |
+|-----|-------------|--------|
+| Multiple inheritance specifiers | `class Foo: Bar, P1, P2` — only first specifier captured | Missing protocol conformance edges |
+| Generic constraints | `class Foo<T: Equatable>` — bounds not tracked | Advanced generics |
+| Conditional conformance | `extension Array: P where Element: Q` — `where` clause not processed | Cross-platform code |
+| Protocol composition | `typealias Codable = Encodable & Decodable` — not expanded | Type alias resolution |
+
+### Export / Visibility
+
+| Gap | Description | Impact |
+|-----|-------------|--------|
+| Nested function declarations | Inner `func` marked as exported — should be private | Conservative resolution still correct (over-exports) |
+
+### Module / Import
+
+| Gap | Description | Impact |
+|-----|-------------|--------|
+| `@testable import` | Test target imports treated as opaque | Test file cross-references |
+| Cross-package SPM imports | External package symbols not resolved | Only affects multi-package repos |
+| `@_exported import` | Module re-exports not tracked | Framework wrapper patterns |
+
+## 🟢 Low Priority
+
+### Type Inference
+
+| Gap | Description | Impact |
+|-----|-------------|--------|
+| `switch` / `case` pattern binding | `case let x as Foo:` not tracked | Enum pattern matching |
+| Tuple destructuring | `let (a, b) = fn()` not handled | Uncommon pattern |
+| `@Environment` / `@EnvironmentObject` | SwiftUI dependency injection — no AST representation | Would need heuristic resolution |
+| `@Query` (SwiftData) | Property wrapper types not inferrable from AST | SwiftData-specific |
+| `#if canImport(...)` | Conditional compilation not evaluated | Cross-platform projects |
+
+## ✅ Resolved
+
+| Gap | Resolution | Commit |
+|-----|-----------|--------|
+| Cross-chunk implicit imports | `addSwiftImplicitImports` now uses `allFileList` instead of chunk-only `files` | `956dfd0` |
+| `private(set)` false positive | Regex excludes `private(set)` / `fileprivate(set)` from unexported check | `0a3cdce` |
+| `if let` / `guard let` binding | `extractIfGuardBinding` handles optional bindings | `16b1a63` |
+| `await` / `try` unwrapping | `unwrapSwiftExpression` strips wrappers before RHS analysis | `16b1a63` |
+| For-loop element type extraction | `extractForLoopBinding` + `extractSwiftElementTypeFromTypeNode` + type_annotation population in type-env | `956dfd0` |
+| `self` / `super` resolution | `lookupInEnv` handles `self`/`super` via AST walk | `16b1a63` |
+| Optional chaining `obj?.method()` | Handled via `optional_chaining_expression` | `16b1a63` |
+| Multi-inheritance specifiers | First specifier captured via `inheritance_specifier` query | `16b1a63` |

type-resolution-system.md

@@ -381,15 +381,15 @@ So return-type-aware receiver inference already exists in a constrained downstre
 | Parameters | Yes | Yes | Yes | Yes | Yes | Yes | Yes | Yes | Yes | Yes | Yes | Yes | Yes |
 | Initializer / constructor inference | Yes | Yes | Yes | Yes | Yes | Yes | Yes | Yes | Yes | Yes | Yes | Yes | Yes |
 | Constructor binding scan | Yes | Yes | Yes | Yes | Yes | Yes | Yes | Yes | Yes | Yes | Yes | Yes | Yes |
-| For-loop element types | Yes | Yes | Yes | Yes | Yes | Yes | Yes | Yes | Yes | Yes | No | Yes | Yes |
-| Pattern binding | Yes | Yes | Yes | Yes | No | Yes | Yes | No | No | No | No | No | No |
+| For-loop element types | Yes | Yes | Yes | Yes | Yes | Yes | Yes | Yes | Yes | Yes | Yes††† | Yes | Yes |
+| Pattern binding | Yes | Yes | Yes | Yes | No | Yes | Yes | No | No | No | Partial‡‡‡ | No | No |
 | Assignment chains | Yes | Yes | Yes | Yes | Yes | Yes | Yes | Yes | Yes | No | Yes | Yes | Yes |
 | Field/property type resolution | Yes | No† | Yes | Yes | Yes | Yes | Yes | Yes* | Yes | YARD | No | Yes | No‡ |
 | Comment-based types | JSDoc | JSDoc | No | No | No | No | No | No | PHPDoc | YARD | No | No | No |
 | Return type extraction | JSDoc | JSDoc | No | No | No | No | No | No | PHPDoc | YARD | No | No | No |
-| Call-result variable binding | Yes | Yes | Yes | Yes | Yes | Yes | Yes | Yes | Yes | Yes¶ | No | Yes | No |
-| Field access binding | Yes | No† | Yes | Yes | Yes | Yes | Yes | No‖ | Yes | N/A | No | Yes | No |
-| Method-call-result binding | Yes | Yes | Yes | Yes | Yes | Yes | Yes | Yes | Yes | Yes¶ | No | Yes | No |
+| Call-result variable binding | Yes | Yes | Yes | Yes | Yes | Yes | Yes | Yes | Yes | Yes¶ | Yes††† | Yes | No |
+| Field access binding | Yes | No† | Yes | Yes | Yes | Yes | Yes | No‖ | Yes | N/A | Yes††† | Yes | No |
+| Method-call-result binding | Yes | Yes | Yes | Yes | Yes | Yes | Yes | Yes | Yes | Yes¶ | Yes††† | Yes | No |
 | Write access (ACCESSES write) | Yes | Yes | Yes | Yes | Yes | Yes | Yes | Yes | Yes§ | Yes | Yes | Yes | No |
 | Parameter types extracted | Yes** | No | Yes | Yes | Yes | Yes | Yes | Partial†† | No | No | No | Yes | No |
 | Method overload disambiguation | Yes** | No | Yes | Yes | Yes | No | No | No | No | No | No | Yes | No |
@@ -423,6 +423,10 @@ So return-type-aware receiver inference already exists in a constrained downstre
 
 ¶¶ C#: `using static NS.Type;` now captured (last segment as class binding). Non-alias `using NS;` still unsupported — namespace imports can't be reduced to per-symbol bindings without type inference.
 
+††† Swift: `extractPendingAssignment` handles `callResult`, `methodCallResult`, `fieldAccess`, and `copy` bindings. `if let` / `guard let` optional bindings supported via `extractIfGuardBinding`. `await` / `try` expression wrappers are unwrapped before RHS analysis. For-loop element type extraction supports `[User]` array sugar and `Array<User>` generics. See `swift-ingestion-gaps.md` for remaining limitations.
+
+‡‡‡ Swift: `if let` / `guard let` optional bindings supported. `while let`, `switch` / `case` pattern matching, and tuple destructuring not yet implemented.
+
 \*\*\* Whole-module-import languages (Go, Ruby, C/C++, Swift): namedImportMap entries synthesized from graph-exported symbols via `synthesizeWildcardImportBindings()`. Not from import AST node extraction.
 
 ---
@@ -458,7 +462,7 @@ Important gaps still remain:
 - no general cross-file propagation of inferred bindings
 - `this`/`self`/`$this` receivers are not resolved in the fixpoint loop (resolved on-demand at call sites via AST walk instead)
 - limited branch-sensitive narrowing outside selected pattern constructs
-- limited Swift support compared with other languages
+- limited Swift support compared with other languages (see `swift-ingestion-gaps.md`)
 - no complete destructuring-based field typing
 - no MRO/inheritance walking for field lookups (`lookupFieldByOwner` is direct-only)
 - for-loop variables bound at walk time cannot see fixpoint-resolved types (Phase 9B gap)