fix(taskprocessing): AppAPI webhook error handling

[joshtrichards]

• Resolves: #

Summary

Harden TaskProcessing AppAPI webhook handling.

• (Commit 1) Validate AppAPI:<exAppId>:<method> webhook methods before parsing and return safely when malformed.
  • Previously, malformed AppAPI: methods were logged but execution continued.
• (Commit 2) Harden error handling for ExApp webhook requests.
  • Pass ExApp request errors as PSR-3 logger context instead of as a scalar value.
  • Previously, logging an array response error could itself throw a TypeError, masking the webhook failure.
  • Catch exceptions thrown by exAppRequest() so failed AppAPI webhook calls do not interrupt task completion.
• (Commit 3) Reformat runWebhook() for readability.
  • Add whitespace and line wrapping, standardize logger formatting, and use early returns to reduce nesting without changing behavior.

TODO

• ...

Checklist

• Code is properly formatted
• Sign-off message is added to all commits
• Tests (unit, integration, api and/or acceptance) are included
• Screenshots before/after for front-end changes
• Documentation (manuals or wiki) has been updated or is not required
• Backports requested where applicable (ex: critical bugfixes)
• Labels added where applicable (ex: bug/enhancement, 3. to review, feature component)
• Milestone added for target branch/version (ex: 32.x for stable32)

AI (if applicable)

• The content of this PR was partly or fully generated using AI