feat(webhook): warn when URL pattern mismatches webhook class

[zimeg]

Summary

• Adds a logger to @slack/webhook (@slack/logger as a new dependency, >=4.0.0)
• IncomingWebhook warns if the URL contains /triggers/ (likely meant for WebhookTrigger)
• WebhookTrigger warns if the URL contains /services/ (likely meant for IncomingWebhook)
• Both classes now accept optional logger and logLevel in their constructor options
• Pattern-based check works for any host (hooks.slack.com, hooks.dev.slack.com, etc.)

Motivation

Users upgrading to v4 of slack-github-action accidentally use webhook-type: webhook-trigger with an incoming webhook URL (or vice versa), causing duplicate deliveries and hangs. This SDK-level warning catches the misconfiguration at construction time regardless of the consumer (GHA, custom scripts, etc.).

Refs: slackapi/slack-github-action#654

Test plan

• Existing tests pass (39/39)
• Biome lint clean
• Build succeeds
• Add unit tests for the warning (logs when URL mismatches, silent when URL matches)

🤖 Generated with Claude Code

[changeset-bot]

🦋 Changeset detected

Latest commit: d33b86c

The changes in this PR will be included in the next version bump.

This PR includes changesets to release 1 package

Name	Type
@slack/webhook	Minor

Not sure what this means? Click here to learn what changesets are.

Click here if you're a maintainer who wants to add another changeset to this PR

[codecov]

Codecov Report

❌ Patch coverage is 96.29630% with 2 lines in your changes missing coverage. Please review.
✅ Project coverage is 89.17%. Comparing base (626da7a) to head (d33b86c).
⚠️ Report is 1 commits behind head on main.
✅ All tests successful. No failed tests found.

Additional details and impacted files

@@            Coverage Diff             @@
##             main    #2688      +/-   ##
==========================================
+ Coverage   89.11%   89.17%   +0.05%     
==========================================
  Files          65       66       +1     
  Lines       10351    10398      +47     
  Branches      473      478       +5     
==========================================
+ Hits         9224     9272      +48     
+ Misses       1096     1095       -1     
  Partials       31       31              

Flag	Coverage Δ
cli-hooks	89.17% <96.29%> (+0.05%)	⬆️
cli-test	89.17% <96.29%> (+0.05%)	⬆️
logger	89.17% <96.29%> (+0.05%)	⬆️
oauth	89.17% <96.29%> (+0.05%)	⬆️
socket-mode	89.17% <96.29%> (+0.05%)	⬆️
web-api	89.17% <96.29%> (+0.05%)	⬆️
webhook	89.17% <96.29%> (+0.05%)	⬆️

Flags with carried forward coverage won't be shown. Click here to find out more.

🚀 New features to boost your workflow:

• 📦 JS Bundle Analysis: Save yourself from yourself by tracking and limiting bundle sizes in JS merges.