fix(firestore-genai-chatbot): ENABLE_DISCUSSION_OPTION_OVERRIDES and ENABLE_GENKIT_MONITORING read the extension's yes as false

[cabljac]

Problem

The extension (GoogleCloudPlatform/firebase-extensions firestore-genai-chatbot/extension.yaml) declares ENABLE_DISCUSSION_OPTION_OVERRIDES and ENABLE_GENKIT_MONITORING as select params with values yes / no, default no.

The kit declares both with defineBoolean (kits/firestore-genai-chatbot/src/config.ts:246 and :253). BooleanParam.value() is process.env.<NAME> === "true", so a .env exported from the extension with yes reads as false: per-document overrides and Genkit monitoring are silently off after migration. The kit descriptions still say If set to "Yes", which no longer matches what the param accepts.

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 the config. 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.

Parity ledger: #2974.