fix(delete-user-data): ENABLE_AUTO_DISCOVERY reads the extension's yes as false

[cabljac]

Problem

The extension declares ENABLE_AUTO_DISCOVERY as a select with values yes / no (delete-user-data/extension.yaml), and its code reads process.env.ENABLE_AUTO_DISCOVERY === "yes" (delete-user-data/functions/src/config.ts:24).

The kit declares it with defineBoolean (kits/delete-user-data/src/config.ts:119). BooleanParam.value() is process.env.ENABLE_AUTO_DISCOVERY === "true", so a .env exported from the extension (ENABLE_AUTO_DISCOVERY=yes) reads as false and auto discovery is silently off after migration.

Same class of bug as #3126, which #3145 fixed for firestore-bigquery-export.

Fix

Match the extension: defineString with input: select({ Yes: "yes", No: "no" }), default no, and a yesNo mapping (value.trim().toLowerCase() === "yes") into config.enableAutoDiscovery. Only yes enables; true reads as off. Update the README config table and add a changelog line. Reference implementation: kits/firestore-bigquery-export/src/config.ts after #3145.

Audit note

All other defineBoolean params across the kits (WILDCARD_IDS, OAUTH_SECURE, IS_ANIMATED, MAKE_PUBLIC, REGENERATE_TOKEN, DO_BACKFILL, UPDATE_ON_CONFIGURE, ENABLE_AUTOMATIC_PUNCTUATION) sit on extension selects that already used true / false, so they are unaffected. The firestore-genai-chatbot pair is the only other case and has its own issue.

Parity ledger: #2974.