feat: make webhook display name suffix configurable

[ornariece]

Summary

Adds a generic.displaynameSuffix config option to control the suffix appended to webhook virtual user display names. Defaults to " (Webhook)" for full backward compatibility.

Motivation

When using generic webhooks in a dedicated room per source (e.g., a monitoring room that receives alerts from one system), the hardcoded (Webhook) suffix in the display name adds no useful information and clutters the UI — especially on mobile clients like Element X where the sender name is shown prominently in push notifications.

Setting displaynameSuffix: "" allows the connection name (e.g., "PVE", "TrueNAS") to be used as-is as the virtual user's display name, which is cleaner when the name already identifies the source.

In multi-source rooms, operators can set a custom suffix like " [alert]" or keep the default.

Changes

• src/config/sections/GenericHooks.ts: Added displaynameSuffix to the YAML config interface and class, defaulting to " (Webhook)"
• src/Connections/GenericHook.ts: Updated ensureDisplayname() to use the configurable suffix instead of the hardcoded string. Added displaynameSuffix to GenericHookServiceConfig

Example config

generic:
  enabled: true
  urlPrefix: https://example.com/hookshot/webhooks/webhook
  userIdPrefix: _webhooks_
  displaynameSuffix: ""  # connection name used as-is

Testing

Tested with hookshot 7.3.2 base. Verified:

• Default behavior unchanged (suffix = " (Webhook)" when not configured)
• Empty string produces clean display names matching the connection name
• Custom suffix strings work as expected

[Half-Shot]

Looks good to me 👍

[Half-Shot]

Hah, went too early. A few CI failures to clean up