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/git/forge-icon.tsx

@@ -0,0 +1,72 @@
+/**
+ * Brand marks are SVG React components, so they cannot travel over the wire as
+ * a string. This file derives icon and brand-color lookup tables from
+ * CLIENT_FORGE_VIEW_MODULES; a new forge ships an icon component in the client
+ * bundle and references it from its view module. Unknown icon kinds fall back to
+ * a generic pull-request glyph.
+ */
+import { withUnistyles } from "react-native-unistyles";
+import { GitPullRequest } from "lucide-react-native";
+import {
+  type ForgeBrandColor,
+  type ForgeIconColorMapping,
+  type ForgeIconComponent,
+} from "@/git/client-forge-module";
+import { CLIENT_FORGE_VIEW_MODULES } from "@/git/forges/view";
+
+const FORGE_ICON_BY_KIND = new Map(
+  CLIENT_FORGE_VIEW_MODULES.map((module) => [module.id, module.icon]),
+);
+
+/**
+ * Raw brand icon component for an `iconKind`, for call sites that style with a
+ * plain `color` prop. Falls back to a generic pull-request glyph.
+ */
+export function getForgeIconComponent(iconKind: string): ForgeIconComponent {
+  return FORGE_ICON_BY_KIND.get(iconKind) ?? GitPullRequest;
+}
+
+const THEMED_ICON_BY_KIND = Object.fromEntries(
+  CLIENT_FORGE_VIEW_MODULES.map((module) => [module.id, withUnistyles(module.icon)]),
+);
+const ThemedGitPullRequest = withUnistyles(GitPullRequest);
+
+/** Theme-driven color mapping, e.g. `(theme) => ({ color: theme.colors.foregroundMuted })`. */
+export type { ForgeIconColorMapping };
+
+function brandColorMapping(colors: ForgeBrandColor): ForgeIconColorMapping {
+  return (theme) => ({ color: theme.colorScheme === "light" ? colors.light : colors.dark });
+}
+
+const BRAND_COLOR_MAPPING_BY_KIND = new Map(
+  CLIENT_FORGE_VIEW_MODULES.flatMap((module) =>
+    module.brandColor ? [[module.id, brandColorMapping(module.brandColor)] as const] : [],
+  ),
+);
+
+/**
+ * The forge's brand color mapping, or null for forges with no dedicated brand
+ * color (github renders in a neutral tone; an unknown forge has none). Call
+ * sites pair this with {@link ForgeBrandIcon}: use it to tint the icon, or to
+ * decide whether to show a brand badge at all.
+ */
+export function getForgeBrandColorMapping(iconKind: string): ForgeIconColorMapping | null {
+  return BRAND_COLOR_MAPPING_BY_KIND.get(iconKind) ?? null;
+}
+
+/**
+ * Themed brand icon for an `iconKind`, for call sites that color via a unistyles
+ * mapping. Falls back to a generic pull-request glyph for unknown forges.
+ */
+export function ForgeBrandIcon({
+  iconKind,
+  size,
+  uniProps,
+}: {
+  iconKind: string;
+  size: number;
+  uniProps: ForgeIconColorMapping;
+}) {
+  const ThemedIcon = THEMED_ICON_BY_KIND[iconKind] ?? ThemedGitPullRequest;
+  return <ThemedIcon size={size} uniProps={uniProps} />;
+}