feat(forge): pluggable forge abstraction + GitLab and Gitea/Forgejo/Codeberg (#1913)

* refactor(forge): forge-neutral foundation (GitHub-only)

Decouple git-hosting from GitHub behind a neutral abstraction (issue #1616), GitHub-only for now; existing GitHub behaviour is unchanged.

- Forge manifest, neutral ForgeService contract, forge registry + resolver, and a client forge-module registry.
- GitHub code renamed to the neutral shape; PR/Issue attachment wording preserved.
- forge.search.response enums parse tolerantly (unknown kind/auth state degrade instead of breaking the client).
- createPullRequest reports typed CLI/auth errors instead of a generic message.
- forge-resolver host/remote caches are LRU-bounded.
- Forge host trust is explicit: only a known cloud host or a CLI-authenticated host is ever talked to; an unauthenticated GitHub Enterprise host fails resolution instead of routing to github.com.
- Docs: forge-providers guide, glossary and i18n forge-copy conventions, architecture and rpc-namespacing terminology.
- Vitest React Native mocks (unistyles, svg, linking, lucide) consolidated into shared aliased test-stubs.

* feat(forge): GitLab adapter, forge-aware UI, pipelines and approvals

GitLab adapter over the glab CLI on the neutral contracts: MR status, forge-aware UI, pipeline tree, and N-of-M approvals.

- threadIsResolved is part of the neutral timeline item.
- Pipeline load failures show an error instead of an empty section.
- Manual pipeline jobs render as pending.
- Fork/detached MR head pipelines are fetched by MR iid (glab ci get --merge-request).

* feat(forge): Gitea family adapter (Gitea, Forgejo, Codeberg)

One adapter over the tea CLI serving Gitea, Forgejo, and Codeberg on the neutral contracts.

- CI status aggregates commit statuses and Actions runs together.
- Gitea's terminal "warning" state maps to failure on server and client.
- Gitea Actions check details are reachable from the PR pane by workflowRunId.

* refactor(forge): localize compatibility handling

* test(forge): expect normalized GitLab facts

---------

Co-authored-by: Mohamed Boudra <boudra.moha@gmail.com>

CLAUDE.md

@@ -37,6 +37,7 @@ At the start of non-trivial work, list `docs/` and skim anything relevant to the
 | [docs/expo-router.md](docs/expo-router.md)                         | Expo Router route ownership, startup restore, and native blank-screen gotchas                                                  |
 | [docs/file-icons.md](docs/file-icons.md)                           | Material icon theme integration for the file explorer                                                                          |
 | [docs/providers.md](docs/providers.md)                             | Adding a new agent provider end-to-end                                                                                         |
+| [docs/forge-providers.md](docs/forge-providers.md)                 | Adding a git forge: registry/manifest, drop-in checklist, self-host/GHES, the two facts tiers                                  |
 | [docs/custom-providers.md](docs/custom-providers.md)               | Custom provider config: Z.AI, Alibaba/Qwen, ACP agents, profiles, custom binaries                                              |
 | [docs/service-proxy.md](docs/service-proxy.md)                     | Service proxy: exposing workspace scripts at public URLs, DNS setup, reverse proxy config                                      |
 | [docs/development.md](docs/development.md)                         | Dev server, build sync gotchas, CLI reference, agent state, Playwright MCP                                                     |