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/contexts/session-context.tsx

@@ -62,7 +62,10 @@ import { derivePendingPermissionKey, normalizeAgentSnapshot } from "@/utils/agen
 import { resolveProjectPlacement } from "@/utils/project-placement";
 import { buildDraftStoreKey } from "@/stores/draft-keys";
 import type { AttachmentMetadata } from "@/attachments/types";
-import { splitComposerAttachmentsForSubmit } from "@/composer/attachments/submit";
+import {
+  resolveComposerAttachmentSubmitFormat,
+  splitComposerAttachmentsForSubmit,
+} from "@/composer/attachments/submit";
 import { reconcilePreviousAgentStatuses } from "@/contexts/session-status-tracking";
 import { patchWorkspaceScripts } from "@/contexts/session-workspace-scripts";
 import {
@@ -728,7 +731,14 @@ function SessionProviderInternal({ children, serverId, client }: SessionProvider
         if (queue && queue.length > 0) {
           const [next, ...rest] = queue;
           if (sendAgentMessageRef.current) {
-            const wirePayload = splitComposerAttachmentsForSubmit(next.attachments);
+            const supportsForgeSearch =
+              useSessionStore.getState().sessions[serverId]?.serverInfo?.features?.forgeSearch ===
+              true;
+            const wirePayload = splitComposerAttachmentsForSubmit(next.attachments, {
+              format: resolveComposerAttachmentSubmitFormat({
+                supportsForgeAttachments: supportsForgeSearch,
+              }),
+            });
             void sendAgentMessageRef.current(
               agent.id,
               next.text,