fix(mcp): allow Claude Code names in tool validation

[justinpbarnett]

Summary

Allow agent tool validation to accept Claude Code formatted MCP tool names when the agent is configured with Forge's legacy MCP tool names or globs.

Problem

Custom agents can be configured with MCP tools using Forge's internal legacy format, for example mcp_github_tool_create_issue or mcp_github_tool_*.

After the Claude Code MCP naming compatibility work, incoming tool calls may arrive as mcp__github__create_issue. MCP execution lookup already accepts both formats, but agent tool validation still checked only the incoming name directly. That caused valid MCP calls to be rejected as not allowed.

Fix

When validating a tool call, continue checking the incoming normalized name and also check its legacy MCP form when the incoming name uses the Claude Code mcp__{server}__{tool} format.

Validation

• Added regression test for exact legacy MCP tool allowlists
• Added regression test for legacy MCP glob allowlists
• Ran cargo test -p forge_app tool_resolver::tests -- --nocapture
• Ran cargo clippy -p forge_app --lib --tests -- -D warnings

[CLAassistant]

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