feat: restore working tree when release fails locally

packages/core/src/index.ts

@@ -3,5 +3,6 @@ export { pathExists, readJson, writeJson } from "./lib/fs.js";
 export * from "./lib/error.js";
 export * from "./lib/exec.js";
 export { execute, resolvePlugins } from "./lib/planner.js";
+export { captureRollbackSnapshot, finalizeRollback } from "./lib/rollback.js";
 export { DefaultStages } from "./lib/stage.js";
 export type * from "./types.js";

packages/core/src/lib/context.ts

@@ -43,4 +43,33 @@ export interface Context {
 	getData<T>(key: string): T;
 	hasData(key: string): boolean;
 	setData(key: string, value: any): void;
+
+	/**
+	 * State used to roll back local changes if the release fails.
+	 * Populated by `captureRollbackSnapshot` before the first non-`check` stage
+	 * that may mutate the working tree.
+	 */
+	rollback?: RollbackState;
+}
+
+export interface RollbackState {
+	/** SHA of HEAD before any release-related modifications were made */
+	originalHead: string;
+	/**
+	 * SHA of the stash commit that holds the user's pre-release uncommitted
+	 * changes (only set when the working tree was dirty, i.e. with --all).
+	 */
+	stashSha?: string;
+	/**
+	 * Unique message used to identify the snapshot stash in `git stash list`,
+	 * since `git stash drop` requires a `stash@{N}` ref rather than a SHA.
+	 */
+	stashMessage?: string;
+	/** Set to true once the push stage starts. Disables rollback afterwards. */
+	pushAttempted: boolean;
+	/**
+	 * Name of the release tag created during this run (e.g. "v1.2.3"). Only set
+	 * after `git tag` succeeds, so rollback never deletes a pre-existing tag.
+	 */
+	createdTag?: string;
 }

packages/core/src/lib/planner.ts

@@ -2,6 +2,7 @@ import { ReleaseError } from "../index.js";
 import type { Context } from "./context.js";
 import { GraphNode, topologicalSort } from "./graph.js";
 import type { Plugin } from "./plugin.js";
+import { captureRollbackSnapshot } from "./rollback.js";
 import { DefaultStages, type Stage } from "./stage.js";
 
 /** Resolve all plugins that are required by the chosen plugins */
@@ -165,8 +166,17 @@ export async function execute(context: Context): Promise<void> {
 			),
 		);
 	}
+	let snapshotTaken = false;
 	for (const stage of stages) {
 		context.cli.prefix = `${stage.id}`;
+		// Snapshot the pre-release state before the first stage that may mutate
+		// the working tree. The `check` stage is read-only by convention; any
+		// later stage (including exec hooks like `after_check` / `before_edit`)
+		// might write files, so we capture before any of those run.
+		if (!snapshotTaken && stage.id !== DefaultStages.check.id) {
+			await captureRollbackSnapshot(context);
+			snapshotTaken = true;
+		}
 		const plugins = await planStage(context, stage);
 		if (context.argv.verbose) {
 			context.cli.log(