Allow to skip signature verification (#664)

## Changes

- Allow skipping signature verification for webhooks

## Motivation

The signature returned with webhooks is calculated using a single
channel secret. If the bot owner changes their channel secret, the
signature for webhooks starts being calculated using the new channel
secret. To avoid signature verification failures, the bot owner must
update the channel secret on their server, which is used for signature
verification. However, if there is a timing mismatch in the update—and
such a mismatch is almost unavoidable—verification will fail during that
period.

In such cases, having an option to skip signature verification for
webhooks would be a convenient way to avoid these issues.

Add new AudienceGroupType POP_AD_IMP to Audience Group API (#650)

line/line-openapi#113

# Add `POP_AD_IMP` to **AudienceGroupType** Enum

We have supported for the new audience‑group type **`POP_AD_IMP`**
(POP ad impression audience) to the OpenAPI schema.

## Changes Made

* **Updated `AudienceGroupType` enumeration**

  * **New value**: `POP_AD_IMP`
* **Description**: Audience groups generated from impressions of *LINE
Beacon Network* (POP) ads.
  * **Region**: **Taiwan‑only** at launch

## Purpose

This update enables correct identification and handling of audience
groups built from POP ad impressions, a feature that will be released
for the Taiwan market.

## Documents and Reference

- [Managing
Audience](https://developers.line.biz/en/reference/messaging-api/#manage-audience-group)

For more information, please refer to the links provided above.

Co-authored-by: github-actions <[email protected]>

Bye line things (#644)

line/line-openapi#112

It has been already gone.
Therefore this change cleans up definition of `ThingsEvent` as one of
webhook event.

Co-authored-by: github-actions <[email protected]>

Add Coupon API Support to Messaging API (#637)

line/line-openapi#111

# Add Coupon API Support to Messaging API
We've supported a set of new APIs that make it possible to create,
manage, and deliver coupons via the Messaging API. These features
provide functionality similar to what's available through the LINE
Official Account Manager interface ([see
here](https://www.lycbiz.com/jp/manual/OfficialAccountManager/coupons-create/)),
allowing developers to integrate coupon-related workflows into their
bots more flexibly.

For more details, see the official announcement:
[LINE Developers News — Coupon API Released
(2025/08/06)](https://developers.line.biz/en/news/2025/08/06/coupon-api/)

## New API Endpoints
- `POST /v2/bot/coupon`
Create a new coupon.
The request includes metadata such as the coupon title, description,
image URLs, validity period, reward details(e.g. 1000yen discount),
acquisition requirements, time zone, etc.

- `GET /v2/bot/coupon`
Retrieve a list of coupons associated with the bot.

- `GET /v2/bot/coupon/{couponId}`
Fetch detailed information about a specific coupon.

- `PUT /v2/bot/coupon/{couponId}`
Mark a coupon as expired.

## Messaging API Update
Message Object now supports a new type: `type=coupon`
This allows developers to send coupons directly to users via the
Messaging API, similar to sending text, image, or template messages.

## Example Requests
### Create a Coupon
```
POST /v2/bot/coupon
Content-Type: application/json
```
#### Request body
```json
{
  "title": "1000 yen off coupon",
  "acquisitionCondition": {
    "type": "normal"
  },
  "visibility": "PUBLIC",
  "startTimestamp": 1672537600,
  "endTimestamp": 1672624000,
  "maxUseCountPerTicket": 1,
  "reward": {
    "type": "discount",
    "priceInfo": {
      "priceInfoType": "fixed",
      "fixedAmount": 1000
    }
  },
  "imageUrl": "https://example.com/coupon_image.png",
  "barcodeImageUrl": "https://example.com/coupon_barcode.png",
  "timezone": "ASIA_TOKYO"
}
```
#### Response
```json
{
  "couponId": "abc1234"
}
```


### Send a Coupon Message

```json
{
  "to": "<userId>",
  "messages": [
    {
      "type": "coupon",
      "couponId": "abc1234"
    }
  ]
}
```

---------

Co-authored-by: github-actions <[email protected]>
Co-authored-by: habara keigo <[email protected]>

Remove old README & Make README_v2 main (#586)

Replace the README in this repository with the README_v2 that we have
prepared.
Merge without reviewing, since there are no changes in the content ,and
it is not time-consuming.

Add an example of narrowcast (#569)

related to #533 
> narrowcast

Fixed a bug that caused the API to request with the replacement of
reserved Ruby characters like `_and`
7eca519

Commit given version on release for rake command

Version 1.29.0

Version 1.28.0

Version 1.27.0