Fix C# phantom symbol extraction suffix-guard regressions

CHANGELOG.md

@@ -10,6 +10,9 @@ The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.1.0/),
 ### [Unreleased]
 
 #### Fixed
+- **C# phantom local `const` and qualified call-site function symbols are now filtered from symbol extraction (#496)** — `SymbolExtractor` now applies the existing column-aware C# type-body gate to field-like `function` rows (`const` / `static readonly`) so local declarations such as `const string content = "hello";` no longer leak into `symbols`, `definition`, or `outline`. It also rejects C# declaration candidates whose captured return-type fragment ends in an operator/contextual suffix, preventing qualified call arguments like `elapsed < TimeSpan.FromSeconds(10)` from surfacing phantom `function FromSeconds` rows. Added a focused regression that locks both repros. Affected: `src/CodeIndex/Indexer/SymbolExtractor.cs`, `tests/CodeIndex.Tests/SymbolExtractorTests.cs`, `CHANGELOG.md`, `DEVELOPER_GUIDE.md`. Closes #496.
+- **C# verbatim-identifier return types no longer get dropped by the #496 suffix guard (#782)** — `HasInvalidCSharpReturnTypeSuffix` now recognizes real C# verbatim identifiers before rejecting contextual-keyword tails, so declarations such as `public @new Make() => new @new();` remain visible in `symbols` and `outline` while the `elapsed < TimeSpan.FromSeconds(...)` phantom-call-site filter stays intact. Added a focused regression for the verbatim return-type repro. Affected: `src/CodeIndex/Indexer/SymbolExtractor.cs`, `tests/CodeIndex.Tests/SymbolExtractorTests.cs`, `CHANGELOG.md`, `DEVELOPER_GUIDE.md`. Closes #782.
+- **C# contextual-keyword type names like `await` / `yield` no longer get dropped by the #496 suffix guard (#785)** — `HasInvalidCSharpReturnTypeSuffix` now keeps legal contextual-identifier type names while still rejecting truly invalid statement/operator tails, so members such as `public await MakeAwait()` and `public yield MakeYield()` remain visible in `symbols`, `definition`, and `outline`. Added a focused regression covering both contextual-keyword return types. Affected: `src/CodeIndex/Indexer/SymbolExtractor.cs`, `tests/CodeIndex.Tests/SymbolExtractorTests.cs`, `CHANGELOG.md`, `DEVELOPER_GUIDE.md`. Closes #785.
 - **C# parenthesized LINQ clause guard no longer mistakes local `const` identifiers for cast targets (#624)** — `ReferenceExtractor` now treats typed local `const` declarations as in-scope value names for the cast-close disambiguation path, so parenthesized `orderby` expressions such as `(READY)` and `(Select)` no longer suppress the real trailing `select(...)` clause solely because the identifier casing looks type-like. Real casts like `(CustomType)select(items)` still keep the clause blocked. Added focused extractor and CLI `references --exact-name --json` regressions for the uppercase-constant repro, and the existing keyword-named-constant regression now passes against the built binary again. Affected: `src/CodeIndex/Indexer/ReferenceExtractor.cs`, `tests/CodeIndex.Tests/ReferenceExtractorTests.cs`, `tests/CodeIndex.Tests/QueryCommandRunnerTests.cs`, `CHANGELOG.md`. Closes #624.
 - **Installer jq-version detection test now uses a real PATH stub instead of a bash function shim (#774)** — `InstallScriptTests.ResolveVersion_UsesJqWhenAvailable` now creates an executable `jq` stub under a temporary directory and prepends that directory to `PATH`, so CI reliably exercises the `command -v jq` branch without depending on bash function lookup details or the runner's preinstalled tools. This keeps the installer's jq-preferring path covered while avoiding spurious stderr on GitHub Actions. Affected: `tests/CodeIndex.Tests/InstallScriptTests.cs`, `CHANGELOG.md`. Closes #774.
 - **Java same-line annotations, enum-constant body overrides, and record compact constructors now extract correctly (#221, #751, #755)** — `SymbolExtractor` now strips leading same-line Java annotations with the existing lexer-aware scanner instead of a flat `[^)]*` regex prefix, so declarations such as `@Label(")") public int broken()`, `@SuppressWarnings({"unchecked"}) public int first() { ... }`, and annotated `record` headers survive string/comment/paren/brace edge cases. The extractor also emits record compact constructors in both same-line (`public Range { ... }`) and Allman-style (`public Range` followed by next-line `{`) layouts, preserves anonymous enum-member body ranges so overrides like `ADD { @Override public int apply(...) { ... } }` attach to the enum constant container, keeps same-line Java brace-bodied siblings separate (`int first() { ... } int second() { ... }`) instead of swallowing later methods into the first signature, and now restarts same-line Java scanning after enum constants so methods inside `A { @Override int f() { ... } int g() { ... } }` also reach the symbol table. Added focused Java regressions for the reported repros plus the enum-member body range contract. Affected: `src/CodeIndex/Indexer/SymbolExtractor.cs`, `tests/CodeIndex.Tests/SymbolExtractorTests.cs`, `CHANGELOG.md`, `DEVELOPER_GUIDE.md`. Closes #221. Closes #751. Closes #755.
@@ -819,6 +822,9 @@ The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.1.0/),
 ### [Unreleased]
 
 #### 修正
+- **C# の phantom なローカル `const` と qualified call-site `function` シンボルが symbol extraction から除外されるよう修正 (#496)** — `SymbolExtractor` は既存の列単位 C# type-body gate を field-like な `function` 行（`const` / `static readonly`）にも適用するようになり、`const string content = "hello";` のようなローカル宣言が `symbols` / `definition` / `outline` へ漏れなくなった。さらに、捕捉した戻り値断片が演算子または contextual suffix で終わる C# 宣言候補も拒否するため、`elapsed < TimeSpan.FromSeconds(10)` のような qualified call 引数から phantom な `function FromSeconds` 行が出なくなる。両 repro を固定する focused regression test も追加。対象: `src/CodeIndex/Indexer/SymbolExtractor.cs`, `tests/CodeIndex.Tests/SymbolExtractorTests.cs`, `CHANGELOG.md`, `DEVELOPER_GUIDE.md`。Closes #496。
+- **C# の verbatim identifier 戻り値型が #496 の suffix guard で落ちなくなるよう修正 (#782)** — `HasInvalidCSharpReturnTypeSuffix` は contextual keyword の末尾を拒否する前に本物の C# verbatim identifier を認識するようになり、`public @new Make() => new @new();` のような宣言は `symbols` / `outline` に残りつつ、`elapsed < TimeSpan.FromSeconds(...)` の phantom call-site 抑止は維持される。verbatim 戻り値型 repro を固定する focused regression test も追加。対象: `src/CodeIndex/Indexer/SymbolExtractor.cs`, `tests/CodeIndex.Tests/SymbolExtractorTests.cs`, `CHANGELOG.md`, `DEVELOPER_GUIDE.md`。Closes #782。
+- **C# の `await` / `yield` のような contextual keyword 型名が #496 の suffix guard で落ちなくなるよう修正 (#785)** — `HasInvalidCSharpReturnTypeSuffix` は合法な contextual identifier 型名を保持しつつ、本当に無効な statement / operator 断片だけを拒否するようになったため、`public await MakeAwait()` や `public yield MakeYield()` のようなメンバーが `symbols` / `definition` / `outline` に再び現れる。両方の contextual-keyword 戻り値型を固定する focused regression test も追加。対象: `src/CodeIndex/Indexer/SymbolExtractor.cs`, `tests/CodeIndex.Tests/SymbolExtractorTests.cs`, `CHANGELOG.md`, `DEVELOPER_GUIDE.md`。Closes #785。
 - **C# の括弧付き LINQ clause guard が、ローカル `const` 識別子を cast target と誤認しないよう修正 (#624)** — `ReferenceExtractor` は cast-close の曖昧性解消で、型付きローカル `const` 宣言も in-scope の値名として扱うようになった。これにより `(READY)` や `(Select)` のような括弧付き `orderby` 式が、識別子の見た目だけで型名扱いされて本物の後続 `select(...)` clause を潰すことがなくなる。一方で `(CustomType)select(items)` のような実際の cast は従来どおり clause をブロックする。uppercase constant repro を固定する focused な extractor / CLI `references --exact-name --json` 回帰を追加し、既存の keyword-named constant 回帰も built binary に対して再び通るようになった。対象: `src/CodeIndex/Indexer/ReferenceExtractor.cs`, `tests/CodeIndex.Tests/ReferenceExtractorTests.cs`, `tests/CodeIndex.Tests/QueryCommandRunnerTests.cs`, `CHANGELOG.md`。Closes #624。
 - **installer の jq 版数取得テストが bash 関数 shim ではなく実 PATH スタブを使うよう修正 (#774)** — `InstallScriptTests.ResolveVersion_UsesJqWhenAvailable` は、一時ディレクトリ配下に実行可能な `jq` スタブを作成し、そのディレクトリを `PATH` の先頭へ差し込むようになった。これにより CI でも `command -v jq` 分岐を bash 関数解決やランナーのプリインストールツールに依存せず確実に通せる。installer 本体の jq 優先経路のカバレッジを維持しつつ、GitHub Actions 上の偽陽性 stderr を防ぐ。対象: `tests/CodeIndex.Tests/InstallScriptTests.cs`, `CHANGELOG.md`。Closes #774。
 - **Java の同一行アノテーション、enum 定数 body override、record compact constructor が正しく抽出されるよう修正 (#221, #751, #755)** — `SymbolExtractor` は Java 宣言の先頭アノテーション処理を平坦な `[^)]*` regex prefix ではなく既存の lexer-aware scanner に寄せ、`@Label(")") public int broken()`、`@SuppressWarnings({"unchecked"}) public int first() { ... }`、注釈付き `record` ヘッダのような文字列/コメント/括弧/波括弧入りケースでも宣言を落とさなくなった。`public Range { ... }` のような record compact constructor も `function` として出し、匿名 enum 定数 body の範囲を保持することで `ADD { @Override public int apply(...) { ... } }` のような override が enum 定数コンテナへぶら下がる。さらに `int first() { ... } int second() { ... }` のような同一行 Java brace-body sibling も最初の signature に飲み込まれず個別に抽出され、`A { @Override int f() { ... } int g() { ... } }` のような same-line enum 定数 body 内メソッドも symbol table まで到達するようになった。issue の repro 群と enum 定数 body range 契約を固定する focused Java 回帰テストも追加。対象: `src/CodeIndex/Indexer/SymbolExtractor.cs`, `tests/CodeIndex.Tests/SymbolExtractorTests.cs`, `CHANGELOG.md`, `DEVELOPER_GUIDE.md`。Closes #221。Closes #751。Closes #755。