feat(check): fail closed on tools and servers in inline check payloads

A PR check runs the branch's agents in a real org, so nothing it sends may
reach a real server by default. The payload builder's last pass now:

- classifies every tool at a handled position (model.tools, tools:append
  in overrides, hook do[], same-org knowledge bases in model.toolIds):
  endCall/dtmf/voicemail/output are sent as written; function tools by
  function.name and apiRequest by name are mocked; transferCall becomes
  a mocked dead-server function; handoffs pass only to squad members or
  inline assistants; everything else (sms, sipRequest, code, mcp,
  integrations, unknown types) fails the build naming the tool;
- fails any tool-bearing key (TOOL_BEARING_KEYS) outside those positions,
  so a new API field can't slip through unclassified;
- replaces servers with https://vapi-gitops-ci.invalid on every assistant
  and function tool rather than deleting them (a deleted server falls back
  to the phone number's or org's), clears serverMessages, and dead-ends
  scenario webhook hooks;
- adds a default error mock for every mocked tool to each scenario's
  toolMocks, replacing disabled ones, and warns about mocks that match no
  tool;
- fails custom knowledge bases, model.knowledgeBaseId, personality tools
  with side effects, hook transfer actions, and cross-org query or
  knowledge-base tools.

`toolMocks: off` skips the tool rules; `stripWebhooks: false` keeps
assistant servers while tool servers are still replaced.

Refs TEST-141

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

Author: scott-lowe-vapi