Improve GitHub branch listing pagination

[HarshMN2345]

No description provided.

[greptile-apps]

Greptile Summary

This PR overhauls listBranches across all four VCS adapters, adding $perPage, $page (integer or cursor string), and $search parameters to the abstract base and each concrete implementation.

• GitHub migrates from the REST paginated endpoint to a GraphQL query with cursor-based pagination and server-side prefix search via refPrefix, returning a structured {items, hasNext, nextCursor} shape instead of the previous flat array — but reaching an integer page N still requires N sequential GraphQL calls, and the abstract base's return type now covers two incompatible shapes.
• GitLab / Gitea / Gogs fetch all branches with their existing looping API calls and apply search filtering and pagination client-side, remaining return-type-incompatible with the GitHub adapter; the Gogs adapter makes a single unpaginated API call with no page or limit query parameters.

Confidence Score: 3/5

Not ready to merge: GitHub returns a different shape from the other three adapters, integer-page access issues N sequential GraphQL calls, and Gogs performs client-side pagination over a potentially server-capped response.

Multiple concrete defects across changed files: GitHub structured return breaks polymorphic callers treating the result as a flat array, N sequential calls make large integer page numbers impractical and rate-limit-prone, and Gogs single unpaginated API call means array_slice pagination can silently return wrong data.

GitHub.php for sequential-call and dead-code issues, Gogs.php for missing API pagination parameters, and Adapter.php for the diverged return-type contract.

Important Files Changed

Filename	Overview
src/VCS/Adapter.php	Abstract listBranches signature updated with new params, but the return type PHPDoc now covers both the old flat array<string> (GitLab/Gitea/Gogs) and the new structured array{items, hasNext, nextCursor} (GitHub), leaving polymorphic callers unable to rely on either form.
src/VCS/Adapter/Git/GitHub.php	Migrated to GraphQL with cursor pagination and server-side prefix search; returns {items, hasNext, nextCursor}. Integer-page access still requires N sequential calls, and the return $result after the loop is unreachable dead code.
src/VCS/Adapter/Git/GitLab.php	Now accepts perPage/page/search params but applies search client-side after fetching all branches; GitLab's API supports a native ?search= parameter that could eliminate unnecessary data transfer. Still returns a flat array, inconsistent with GitHub's structured return.
src/VCS/Adapter/Git/Gitea.php	Now accepts perPage/page/search params but filters client-side; Gitea's branch API supports ?q= for server-side search. Returns a flat array inconsistent with GitHub's structured return.
src/VCS/Adapter/Git/Gogs.php	Accepts all new params but makes a single unpaginated API call with no page/limit query params; if Gogs server applies a default result cap, client-side array_slice pagination silently operates on a truncated dataset.
tests/VCS/Adapter/GitHubTest.php	Tests updated to validate the new structured return shape, cursor-based pagination, and prefix search; assertions are well-structured and cover the main scenarios.
tests/VCS/Adapter/GitLabTest.php	Pagination test assertions compare $result[0] / $result[1] from an unordered full-fetch against deterministic page slices; order is consistent only if GitLab API always returns branches in alphabetical order, which is the default but not guaranteed.
tests/VCS/Adapter/GiteaTest.php	Same ordering-assumption fragility as GitLabTest — $branches[0] and $branches[1] from a full fetch are compared against paginated slices without asserting or controlling sort order.

_{Reviews (4): Last reviewed commit: "Preserve default branch listing behavior" | Re-trigger Greptile}