Standardize discovery pagination and grouped metadata

TESTING_GUIDE.md

@@ -176,6 +176,9 @@ Use `docs/test-doc-maintenance-plan.md` before moving oversized suites or adding
   CLI parsing, command execution, and installer behavior. Index command coverage is split by run mode or feature area, and query command coverage is split by command family with partial test classes so shared console and fixture helpers stay centralized. Keep repeated query-result fixtures, such as overlapping chunk content used by multiple search deduplication tests, in narrow class-level helpers instead of duplicating local builders. `ProgramCliTests.cs` covers top-level entrypoint behavior that must be exercised through a subprocess, while `InstallScriptTests.cs` runs focused bash snippets against `install.sh` in library mode to lock in release-installer regressions without performing real network installs. Installer bundle-generation tests must also verify that `install.sh` is marked generated while every canonical `install_modules/` source remains unmarked.
   `ConsoleUiTests.cs` keeps each generated shell's complete long-flag catalog aligned with `CliFlagSchema` and checks every Fish command scope against the shared per-command completion projection. Add flags to the schema rather than weakening this Bash / Zsh / Fish / PowerShell parity contract.
   `ProgramRunnerTests.cs` enumerates `CliCommandCatalog.CommandSubcommands` and requires every valid nested verb to resolve to verb-specific usage with an example. It also pins destructive index confirmation and aggregate dependency-filter help, plus the read-only GitHub duplicate-preflight boundary for suggestion exports.
+  Grouped-search limit coverage must seed more matches and files than the returned page, then assert query-wide matched/group/file totals separately from grouped, emitted, and omitted row counts so a bounded page cannot report itself as complete.
+  Cursor-pagination coverage for `outline` and `unused` must replay the emitted opaque token successfully, then prove that changed filters/order and a changed index-generation stamp fail with restart-required diagnostics.
+  Discovery-pagination coverage must page compact search/symbol/file output and the opt-in search-array/languages envelopes, assert authoritative total/omitted/stable-at metadata, reject query or generation cursor mismatches, and prove that a partial `find --all` scan resumes after the last scanned line.
   Quiet-flag coverage in `ProgramCliTests.cs` reuses one seeded symbols database across text, NDJSON, and JSON-array modes and compares stdout with and without a trailing quiet alias, proving that quiet mode changes only informational stderr.
   Doctor full-inventory coverage keeps composed filter selection, filtered summary counts, exact UTF-8 byte-budget boundaries, and structured overflow errors together in `ProgramRunnerTests`; license JSON remains a subprocess contract in `ProgramCliTests` so immediate-command dispatch and the published field names are both exercised.
   Ctags export JSON coverage reuses one seeded database for default and `--include-generated` variants, asserts the fixed skip-reason keys sum to `skipped_count`, and keeps the missing-`files.generated` degradation in a separate legacy-schema fixture.
@@ -1021,6 +1024,9 @@ dotnet test --filter "FullyQualifiedName~GitHelperTests"
   CLI の引数解析、コマンド実行、installer 挙動のテスト。Index command coverage は run mode または機能領域ごとの partial suite に分割し、Query command coverage は command family ごとの partial test class に分割して、共有 console / fixture helper は一箇所に保ちます。`ProgramCliTests.cs` はグローバル引数の解釈や完全な CLI 起動フローのように subprocess 経由で確認すべき Program エントリポイント挙動を扱い、`InstallScriptTests.cs` は `install.sh` を library mode で source した bash snippet を実行して、実ネットワーク install を行わずに release installer の回帰を固定する。installer bundle 生成テストでは、`install.sh` が generated と判定される一方、canonical な `install_modules/` source はすべて unmarked のままであることも検証してください。
   `ConsoleUiTests.cs` は各生成シェルの long flag 全カタログを `CliFlagSchema` と同期させ、Fish の全 command scope を共有の command 別 completion 射影と照合します。この Bash / Zsh / Fish / PowerShell parity 契約を弱めず、新しい flag は schema に追加してください。
   `ProgramRunnerTests.cs` は `CliCommandCatalog.CommandSubcommands` を列挙し、すべての有効な nested verb が例を含む verb 固有 usage に解決されることを必須とします。さらに destructive な index confirmation、aggregate dependency filter help、suggestion export の read-only GitHub duplicate-preflight 境界を固定します。
+  grouped search の limit coverage では、返却 page より多い match と file を seed し、query 全体の match/group/file 総数と grouped、emitted、omitted row 数を別々に検証して、上限付き page が完了済みと報告できないようにしてください。
+  `outline` と `unused` の cursor pagination coverage では、出力された opaque token の再利用成功に加え、filter/order の変更と index-generation stamp の変更が restart-required 診断で失敗することを検証してください。
+  discovery pagination の coverage では compact search / symbol / file と opt-in の search array / languages envelope をページングし、authoritative な total / omitted / stable-at metadata、query / generation 不一致 cursor の拒否、partial な `find --all` scan が最後に scan した line の次から再開することを検証してください。
   `ProgramCliTests.cs` の quiet flag coverage は1つの seeded symbols database を text、NDJSON、JSON array の各 mode で再利用し、末尾に quiet alias を付けた場合と付けない場合の stdout を比較して、quiet mode が informational stderr だけを変えることを固定します。
   doctor full-inventory coverage では、合成 filter の選択、filtered summary 件数、UTF-8 byte budget の exact boundary、structured overflow error を `ProgramRunnerTests` にまとめます。license JSON は `ProgramCliTests` の subprocess contract として、immediate-command dispatch と公開 field 名を同時に検証します。
   ctags export JSON coverage は1つの seeded database を既定と `--include-generated` variant で再利用し、固定された skip-reason key の合計が `skipped_count` と一致することを検証します。`files.generated` がない場合の縮退は別の legacy-schema fixture に保ってください。