fix(core): warn when dynamic tools.eager entries match no discovered tool #12435

What happened?

tools.eager accepts dynamic tool names such as mcp__* and computer_use__*, but a typo in one of those names is accepted silently.

For example, configuring:

{
  "tools": {
    "eager": ["mcp__githb__create_issue"]
  }
}

activates the allowlist without matching a discovered tool. As a result, every non-exempt tool is deferred to tool_search, with no startup diagnostic explaining the unexpected tool surface.

This is the remaining diagnostic gap from #10400. Its other items are covered by #10479.

What did you expect to happen?

After the relevant dynamic tool-discovery cycle completes, Qwen Code should warn when a configured mcp__* or computer_use__* eager entry matches no registered tool. Valid entries must remain silent.

Client information

Observed against current main during repository maintenance. The behavior is configuration-driven and does not depend on a particular provider or operating system.

Anything else we need to know?

Do not validate these names during PermissionManager.initialize(): MCP tools can be registered after initialization, so that would produce false warnings. The validation needs a registry-aware completion boundary that handles incremental MCP discovery and canonical tool names.

Suggested coverage:

• typoed MCP and Computer Use entries warn;
• valid dynamic entries do not warn;
• late registration does not produce a premature warning;
• warnings are emitted once per unmatched entry.