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>

packages/app/src/screens/new-workspace-picker-item.test.ts

@@ -1,9 +1,9 @@
 import { describe, expect, it } from "vitest";
-import type { GitHubSearchItem } from "@getpaseo/protocol/messages";
+import type { ForgeSearchItem } from "@getpaseo/protocol/messages";
 import { pickerItemToCheckoutRequest, type PickerItem } from "./new-workspace-picker-item";
 
-const prItem: GitHubSearchItem = {
-  kind: "pr",
+const prItem: ForgeSearchItem = {
+  kind: "change_request",
   number: 42,
   title: "Add picker",
   url: "https://example.com/pull/42",
@@ -35,6 +35,7 @@ describe("pickerItemToCheckoutRequest", () => {
     expect(pickerItemToCheckoutRequest(item)).toEqual({
       action: "checkout",
       refName: "feature/picker",
+      checkoutSource: { kind: "change_request", forge: "github", number: 42 },
       githubPrNumber: 42,
     });
   });
@@ -53,7 +54,31 @@ describe("pickerItemToCheckoutRequest", () => {
     expect(pickerItemToCheckoutRequest(item)).toEqual({
       action: "checkout",
       refName: "orphan",
+      checkoutSource: { kind: "change_request", forge: "github", number: 7 },
       githubPrNumber: 7,
     });
   });
+
+  it("does not send the legacy githubPrNumber for non-GitHub change requests", () => {
+    const item: PickerItem = {
+      kind: "github-pr",
+      item: {
+        ...prItem,
+        forge: "gitlab",
+        number: 21,
+        projectPath: "acme/repo",
+        url: "https://gitlab.example.com/acme/repo/-/merge_requests/21",
+      },
+    };
+    expect(pickerItemToCheckoutRequest(item)).toEqual({
+      action: "checkout",
+      refName: "feature/picker",
+      checkoutSource: {
+        kind: "change_request",
+        forge: "gitlab",
+        number: 21,
+        projectPath: "acme/repo",
+      },
+    });
+  });
 });