feat(github): add pull request level actions

[Harry19081]

Problem

ORGII's shared GitHub pull-request pages expose conversation reviews but do not provide the pull-request lifecycle controls available in GitHub. Users must leave ORGII to merge, enable merge automation, manage requested reviewers, or close and reopen a pull request. The different PR hosts also need one authoritative implementation so their status and controls cannot drift.

Solution

Add one borderless, background-free PR-level action row to the shared PrDetailPanel, which covers Source Control, My Station, tabs, and chat-hosted PR views. The row supports repository-allowed merge methods, expected-head guards, auto-merge, merge-queue enqueue/dequeue behavior, direct reviewer requests/removals, and close/reopen. Existing whole-PR Approve, Request changes, and Comment controls remain in Conversation.

Add typed Tauri commands and REST/GraphQL payloads for those mutations. Every action flows through one scoped mutation dispatcher and reconciles the authoritative PR bundle afterward. Merge metadata and merge-queue state are loaded concurrently with the existing compare request, and the lifted tab header derives status from the refreshed detail.

The API shapes follow GitHub's documented pull-request merge endpoint, review-request endpoints, and current GraphQL input schema.

Potential risks

GitHub repository policies, branch protection, token permissions, and transient mergeability can still reject an action after the UI presents it; server errors are surfaced and the panel reconciles after both success and failure. PR detail now makes one best-effort GraphQL metadata request in parallel with its existing compare request, which adds API/rate-limit cost; a metadata failure degrades to the existing REST state rather than failing the detail page. Reviewer management currently supports direct users returned by the repository's assignable-user source, not team review requests.

No live destructive GitHub mutation or desktop screenshot was performed. The PR remains Draft pending a signed-in visual/action pass. Rollback is reverting commit 22759aa87; there is no schema, persistence, configuration, dependency, or public wire-format migration.

Verification

• npx vitest run src/api/tauri/github/pullRequests.test.ts src/shared/pr/prLevelActions.test.ts src/modules/WorkStation/CodeEditor/Panels/EditorPrimarySidebar/content/PullRequestContent/detail/PrConversationTab.test.ts src/modules/WorkStation/CodeEditor/Panels/EditorPrimarySidebar/content/PullRequestContent/detail/PrDetailPanel.test.ts src/modules/WorkStation/CodeEditor/Panels/EditorPrimarySidebar/hooks/useWorkstationPrDetail.test.ts — 5 files, 22 tests passed.
• npx tsc --noEmit --pretty false — passed.
• npx eslint src/api/tauri/github/pullRequests.ts src/api/tauri/github/pullRequests.test.ts src/shared/pr/prLevelActions.ts src/shared/pr/prLevelActions.test.ts src/modules/WorkStation/CodeEditor/Panels/EditorPrimarySidebar/content/PullRequestContent/detail/PrLevelActions.tsx src/modules/WorkStation/CodeEditor/Panels/EditorPrimarySidebar/content/PullRequestContent/detail/PrDetailPanel.tsx src/modules/WorkStation/CodeEditor/Panels/EditorPrimarySidebar/content/PullRequestContent/detail/PrDetailPanel.test.ts src/modules/WorkStation/CodeEditor/Panels/EditorPrimarySidebar/content/PullRequestContent/detail/PrConversationTab.test.ts src/modules/WorkStation/CodeEditor/Panels/EditorPrimarySidebar/hooks/useWorkstationPrDetail.ts src/modules/WorkStation/CodeEditor/Panels/EditorPrimarySidebar/hooks/useWorkstationPrDetail.test.ts src/modules/WorkStation/TabContent/renderers/githubPrDetail.tsx src/store/workstation/codeEditor/workstationSelectedPrAtom.ts — passed.
• cargo clippy -p integrations --all-targets -- -D warnings — passed.
• cargo test -p integrations pr_action_payload_tests --lib — 6 tests passed.
• rustfmt --edition 2021 --check crates/integrations/src/github/client.rs crates/integrations/src/github/commands/pulls.rs — passed.
• git diff --cached --check and the repository pre-commit hook — passed; the hook reran lint-staged, TypeScript, scoped Rust clippy, and staged-file integrity checks.
• Read-only GitHub GraphQL introspection confirmed the enable/disable-auto-merge and enqueue/dequeue input fields; the merge-metadata query was also accepted by the current schema.

Audit

• Architecture audit covered compile/type integrity, one shared mutation owner, canonical merge-method/state vocabulary, failure defaults, REST/GraphQL payload contracts, shared-host initialization parity, and repo/head-SHA ownership.
• Manual frontend consistency pass found the action row uses existing Button, Dropdown, Avatar, Message, and detail-panel tokens; it wraps at narrow widths and adds no enclosing background or border. The configured frontend-ui-audit skill was not present in this checkout, so no skill-format report was generated.
• Scope audit found 16 changed files, all tied to PR-level actions and their tests. No new inline-review, file-viewed, dependency, generated artifact, secret, debug-log, personal-path, or trail-navigation change is included.