refactor(appkit): trim ui-variants choice-sink to minimal helper adoption

Route the ui-variants choices JSONL path through getEphemeralStateDir()
without the incidental churn: keep the single UI_CHOICES_FILE constant and
the original constructor signature, and restore the main docstrings (with
only the accuracy fix the now-absolute path requires).

Co-authored-by: Isaac
Signed-off-by: Atila Fassina <atila@fassina.eu>

Author: atilafassina

packages/appkit/src/plugins/ui-variants/choice-sink.ts

@@ -3,28 +3,22 @@ import path from "node:path";
 import { getEphemeralStateDir } from "shared/cli/commands/cache-paths";
 
 /**
- * Filename of the JSONL choices file. The agent skill discovers this file at
- * the ephemeral state directory (under node_modules/).
- */
-const UI_CHOICES_FILENAME = ".appkit-ui-choices.jsonl";
-
-/**
- * Default absolute path to the JSONL choices file: ephemeral state dir
- * (node_modules/.databricks/appkit/) + the contract filename. Kept
- * ephemeral & gitignored; NOT part of the committed .appkit/ relocation.
- *
+ * Absolute path of the JSONL choices file, under `node_modules/`.
  * A coding agent reads it to pick up the developer's in-browser confirmation
- * and finalize the chosen variant. Each line is spent on read — the agent
- * removes it once the choice is finalized.
+ * and finalize the chosen variant.
+ *
+ * Under `node_modules/`, so it's gitignored and cleared on a clean install.
+ * Each line is spent on read — the agent removes it once the choice is
+ * finalized.
  *
  * CONTRACT: the `databricks-app-variants` agent skill (in the
- * databricks-agent-skills repo) discovers the choices file at this absolute
- * path. Changing this value silently breaks that skill's file discovery —
- * update the skill's `find` path in the same change.
+ * databricks-agent-skills repo) discovers the choices file at this path.
+ * Changing this value silently breaks that skill's file discovery — update the
+ * skill's `find` path in the same change.
  */
-const DEFAULT_UI_CHOICES_PATH = path.join(
+const UI_CHOICES_FILE = path.join(
   getEphemeralStateDir(),
-  UI_CHOICES_FILENAME,
+  ".appkit-ui-choices.jsonl",
 );
 
 /**
@@ -51,16 +45,14 @@ export interface UiChoiceRecord {
 
 /**
  * File store for confirmed variant choices: upserts choices into
- * {@link DEFAULT_UI_CHOICES_PATH}, one line per `<Variants>` id.
+ * {@link UI_CHOICES_FILE}, one line per `<Variants>` id.
  *
  * The store is **keyed and latest-wins**: at most one record per `blockId`, and
  * recording an existing `blockId` replaces it rather than appending, so the file
  * always reflects the current choice for each block.
  *
- * By default, the file lands at the ephemeral state directory under
- * `node_modules/.databricks/appkit/`. Callers may override the path (e.g., for
- * testing), in which case it is resolved against `process.cwd()`; absolute
- * paths are passed through unchanged. Concurrent confirms are serialized behind
+ * The file is resolved against `process.cwd()`, so it lands under whatever
+ * directory the dev server runs from. Concurrent confirms are serialized behind
  * an internal queue so their read-modify-write can't interleave and lose an
  * update.
  *
@@ -70,8 +62,8 @@ export class FileChoiceStore {
   private readonly filePath: string;
   private writeQueue: Promise<void> = Promise.resolve();
 
-  constructor(pathArg: string = DEFAULT_UI_CHOICES_PATH) {
-    this.filePath = path.resolve(process.cwd(), pathArg);
+  constructor(relativePath: string = UI_CHOICES_FILE) {
+    this.filePath = path.resolve(process.cwd(), relativePath);
   }
 
   record(record: UiChoiceRecord): Promise<void> {