Feature Request: Add `get_unbound_breakpoints` tool

[MarcAButler]

Summary

Add a new MCP tool called get_unbound_breakpoints that returns all breakpoints currently set but not verified (i.e., not successfully bound to an executable line) by the debug adapter.

Problem

DebugMCP's existing add_breakpoint tool gives no feedback on whether a breakpoint actually bound successfully. If the lineContent parameter doesn't match the file exactly (see #18), or the file isn't loaded yet, the breakpoint is silently registered but never verified. The existing list_breakpoints tool lists all breakpoints without distinguishing between verified and unverified ones, leaving the agent with no way to detect or diagnose the failure.

This means an agent can confidently believe it has set a breakpoint, proceed to run the program, and never understand why execution never paused.

Proposed Solution

Add a get_unbound_breakpoints tool that queries VS Code's vscode.debug.breakpoints collection and filters for breakpoints where verified === false.

Requirements:

• No parameters required
• Should work at any point during a debug session
• Returns an array of unverified breakpoints with file and line information
• Returns an empty array (not an error) if all breakpoints are verified