feat(protected_environments): edit deploy group membership

[sjungwon03]

Summary

Project protected environments can now switch an existing deploy group's membership between direct members only and inherited members. The dialog shows the actual reported mode and requires a changed selection, exact environment name and acknowledgement before saving.

Only the selected grant's ID and group_inheritance_type are sent. Complete inventory/detail preflight and strict response/read-back checks preserve group identity, reported role metadata, every other deploy grant, approval rules and legacy approval count. Unknown membership and group-level rules remain read-only; account changes and uncertain writes require a fresh inspection and confirmation.

Closes #658

Validation

• dart format --output=none --set-exit-if-changed .
• flutter analyze reports no issues
• Full app and package suites: 8,514 tests passed (app 4,834; API 3,336; design system 135; models 204; secure storage 5)
• Related controller/widget regression suite: 196 passing tests; dedicated API tests: 27 passing tests
• API, controller and widget tests were run red before their implementation, then green
• Localization regenerated for English, Korean, Japanese, Hindi and Chinese
• No models changed; build_runner is not applicable
• CI English-language policy and whitespace checks
• Synthetic widget captures inspected at mobile and desktop widths in light and dark themes; no live GitLab validation performed

Checklist

• Targets dev and links one issue
• Conventional Commits with DCO sign-off
• Test-first implementation and updated behavior documentation
• Five locales tested at 320/800/1200 widths in light and dark themes
• No new dependencies or third-party assets added
• Fixtures and screenshots contain no credentials, real instance hostnames or confidential data
• Repository text is English except supported locale translations

Screenshots

Fixture-only captures show the confirmation portion of the scrollable dialog.

Viewport	Light	Dark
Mobile, 390 × 844
Desktop, 1200 × 900

Notes for reviewers

GitLab's group inheritance types also apply to deploy grants. The update endpoint can report access_level alongside a deploy group_id; that metadata is accepted and preserved rather than treating the grant as a role-only entry. The write disables redirects and automatic OAuth refresh/replay, maps status errors before parsing, and uses the existing strict full-rule reader.

The endpoint has no atomic compare-and-set, so preflight and read-back cannot eliminate concurrent server changes. Preservation covers modelled fields. Premium/Ultimate, CI/CD, management permissions and sharing the group with the project are server requirements; no live tier, role or self-hosted version matrix was validated. Grant creation/removal and principal/role replacement are outside this slice.

See implementation and evidence.

[sjungwon03-ai]

Review summary

Verdict: Approved

• Reviewed: deploy-group membership editing API, controller, dialog, localization, and regression coverage
• Checks: CI completed successfully (iOS SDK validation, Flutter quality gate, language policy, and triage)