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/issue-provider.ts

@@ -0,0 +1,80 @@
+/**
+ * IssueProvider — Abstract interface for issue tracker operations.
+ *
+ * GitLab is the first implementation (via glab CLI).
+ * Future providers: GitHub (via gh CLI), Jira (via API).
+ *
+ * All DevClaw tools operate through this interface, making it possible
+ * to swap issue trackers without changing tool logic.
+ */
+
+export const STATE_LABELS = [
+  "Planning",
+  "To Do",
+  "Doing",
+  "To Test",
+  "Testing",
+  "Done",
+  "To Improve",
+  "Refining",
+] as const;
+
+export type StateLabel = (typeof STATE_LABELS)[number];
+
+export const LABEL_COLORS: Record<StateLabel, string> = {
+  Planning: "#6699cc",
+  "To Do": "#428bca",
+  Doing: "#f0ad4e",
+  "To Test": "#5bc0de",
+  Testing: "#9b59b6",
+  Done: "#5cb85c",
+  "To Improve": "#d9534f",
+  Refining: "#f39c12",
+};
+
+export type Issue = {
+  iid: number;
+  title: string;
+  description: string;
+  labels: string[];
+  state: string;
+  web_url: string;
+};
+
+export interface IssueProvider {
+  /** Create a label if it doesn't exist (idempotent). */
+  ensureLabel(name: string, color: string): Promise<void>;
+
+  /** Create all 8 state labels (idempotent). */
+  ensureAllStateLabels(): Promise<void>;
+
+  /** Create a new issue. */
+  createIssue(title: string, description: string, label: StateLabel, assignees?: string[]): Promise<Issue>;
+
+  /** List issues with a specific state label. */
+  listIssuesByLabel(label: StateLabel): Promise<Issue[]>;
+
+  /** Fetch a single issue by ID. */
+  getIssue(issueId: number): Promise<Issue>;
+
+  /** Transition an issue from one state label to another (atomic unlabel + label). */
+  transitionLabel(issueId: number, from: StateLabel, to: StateLabel): Promise<void>;
+
+  /** Close an issue. */
+  closeIssue(issueId: number): Promise<void>;
+
+  /** Reopen an issue. */
+  reopenIssue(issueId: number): Promise<void>;
+
+  /** Check if an issue has a specific state label. */
+  hasStateLabel(issue: Issue, expected: StateLabel): boolean;
+
+  /** Get the current state label of an issue. */
+  getCurrentStateLabel(issue: Issue): StateLabel | null;
+
+  /** Check if any merged MR/PR exists for a specific issue. */
+  hasMergedMR(issueId: number): Promise<boolean>;
+
+  /** Verify the provider is working (CLI available, auth valid, repo accessible). */
+  healthCheck(): Promise<boolean>;
+}