feat: Implement GitLabProvider for issue management using glab CLI

- Add GitLabProvider class for handling issue operations, label management, and MR checks.
- Implement methods for ensuring labels, creating issues, listing issues by label, and transitioning labels.
- Introduce a provider factory to auto-detect GitLab or GitHub based on the repository URL.
- Create project registration tool to validate repositories, create state labels, and log project entries.
- Enhance queue status and session health tools to support new session management features.
- Update task completion and task creation tools to support auto-chaining and improved session handling.
- Refactor task pickup tool to streamline model selection and session management.

lib/providers/index.ts

@@ -0,0 +1,54 @@
+/**
+ * Provider factory — creates the appropriate IssueProvider for a repository.
+ *
+ * Auto-detects provider from git remote URL:
+ *   - github.com → GitHubProvider (gh CLI)
+ *   - Everything else → GitLabProvider (glab CLI)
+ *
+ * Can be overridden with explicit `provider` option.
+ */
+import { execFileSync } from "node:child_process";
+import type { IssueProvider } from "../issue-provider.js";
+import { GitLabProvider } from "./gitlab.js";
+import { GitHubProvider } from "./github.js";
+
+export type ProviderOptions = {
+  provider?: "gitlab" | "github";
+  glabPath?: string;
+  ghPath?: string;
+  repoPath: string;
+};
+
+function detectProvider(repoPath: string): "gitlab" | "github" {
+  try {
+    const url = execFileSync("git", ["remote", "get-url", "origin"], {
+      cwd: repoPath,
+      timeout: 5_000,
+    }).toString().trim();
+
+    if (url.includes("github.com")) return "github";
+    return "gitlab";
+  } catch {
+    return "gitlab";
+  }
+}
+
+export type ProviderWithType = {
+  provider: IssueProvider;
+  type: "github" | "gitlab";
+};
+
+export function createProvider(opts: ProviderOptions): ProviderWithType {
+  const type = opts.provider ?? detectProvider(opts.repoPath);
+
+  if (type === "github") {
+    return {
+      provider: new GitHubProvider({ ghPath: opts.ghPath, repoPath: opts.repoPath }),
+      type: "github",
+    };
+  }
+  return {
+    provider: new GitLabProvider({ glabPath: opts.glabPath, repoPath: opts.repoPath }),
+    type: "gitlab",
+  };
+}