Require evidence for ban, tempban, and kick moderation actions

[ToxicBiohazard]

Types of changes

What types of changes does your code introduce?
Put an x in the boxes that apply.

• Bugfix (non-breaking change which fixes an issue).
• New feature (non-breaking change which adds functionality).
• Breaking change (fix or feature that would cause existing functionality not to work as expected).
• Documentation Update (if none of the other choices applies).

Proposed changes

Moderation actions now require non-empty evidence across Discord commands and platform ban webhooks.

• Make evidence a required parameter on /ban, /tempban, and /kick
• Add shared validate_evidence() validation and reject blank or whitespace-only values
• Remove the "none provided" fallback when banning through the helper layer
• Require non-empty notes for platform account_banned webhook events (HTTP 400 when missing)
• Add unit tests for missing/blank evidence in commands, helpers, and webhook handlers

This ensures every ban or kick is backed by documented evidence for moderation review and audit trails.

Checklist

Put an x in the boxes that apply.

• I have read and followed the CONTRIBUTING.md
  doc.
• Lint and unit tests pass locally with my changes.
• I have added the necessary documentation (if appropriate).

Additional context

Platform integrations sending account_banned events must include a non-empty notes field. Moderators using slash commands must provide evidence when issuing bans or kicks.

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 65.36%. Comparing base (52a14f7) to head (669f116).

Additional details and impacted files

@@            Coverage Diff             @@
##             main     #188      +/-   ##
==========================================
+ Coverage   65.18%   65.36%   +0.18%     
==========================================
  Files          52       52              
  Lines        3056     3069      +13     
==========================================
+ Hits         1992     2006      +14     
+ Misses       1064     1063       -1     

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[Copilot]

Pull request overview

This PR enforces that moderation actions (ban/tempban/kick and platform account_banned webhook bans) include non-empty evidence/notes to support auditability and moderation review.

Changes:

• Makes evidence a required slash-command argument for /ban, /tempban, and /kick, and validates blank/whitespace-only evidence.
• Adds webhook-side validation requiring non-empty notes for ACCOUNT_BANNED events and uses those notes as ban evidence.
• Adds/updates unit tests covering missing/blank evidence/notes across commands, helpers, and webhook handlers.

Reviewed changes

Copilot reviewed 9 out of 9 changed files in this pull request and generated 2 comments.

Show a summary per file

File	Description
tests/src/webhooks/handlers/test_base.py	Adds unit tests for new non-empty string validation helper.
tests/src/webhooks/handlers/test_account.py	Adds coverage that ACCOUNT_BANNED rejects missing notes.
tests/src/helpers/test_ban.py	Adds coverage for rejecting blank evidence in ban helper logic.
tests/src/cmds/core/test_user.py	Updates kick tests for required evidence and adds blank-evidence rejection test.
src/webhooks/handlers/base.py	Introduces validate_non_empty_string() for webhook payload validation.
src/webhooks/handlers/account.py	Requires non-empty notes for account bans and passes notes as evidence.
src/helpers/ban.py	Adds shared validate_evidence() and removes fallback evidence behavior.
src/cmds/core/user.py	Makes kick evidence required and validates evidence before kicking.
src/cmds/core/ban.py	Makes ban/tempban evidence required in command signatures.

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[0xRy4n]

LGTM