feat(notification): allow customizable notification message

[CalvinAllen]

Summary

Allow users to customize the notification message text via settings, with support for placeholder variables.

Motivation

Different developers have different preferences:

• Some want minimal: "BP Hit"
• Some want detailed: "Breakpoint triggered - time to check the debugger!"
• Some want context: "{file}:{line} - Breakpoint Hit"

Implementation

Add a settings field for custom message format with placeholder support.

Available Placeholders

Code context:

• {file} - File name (e.g., "UserService.cs")
• {filepath} - Full file path
• {line} - Line number
• {method} - Method name
• {class} - Class/type name
• {namespace} - Namespace
• {project} - Project name

Breakpoint metadata:

• {hitcount} - How many times this breakpoint has been hit this session
• {condition} - The condition expression (if conditional breakpoint)
• {label} - User-assigned breakpoint label/name

Session/timing:

• {time} - Current time (HH:mm:ss)
• {elapsed} - Time since debug session started
• {delta} - Time since last breakpoint hit

Process/thread:

• {process} - Process name
• {pid} - Process ID
• {thread} - Thread name or ID

Environment:

• {solution} - Solution name
• {config} - Build configuration (Debug/Release)
• {branch} - Current git branch

Default

Breakpoint Hit! (current behavior)

Example Custom Formats

• {file}:{line} → "UserService.cs:42"
• Breakpoint in {method} → "Breakpoint in GetUserById"
• [{time}] BP: {file}:{line} → "[14:32:05] BP: UserService.cs:42"
• [{branch}] {class}.{method} → "[feature/auth] UserService.GetUserById"
• Hit #{hitcount}: {file}:{line} → "Hit Welcome to VS-BreakpointNotifier Discussions! #3: UserService.cs:42"

Considerations

• Gracefully handle missing placeholder values (show empty string or placeholder name)
• Provide a reasonable default
• Works in combination with notification style toggle (MessageBox/Toast/Both)
• Depends on Show file and line number in breakpoint notification #5 for extracting contextual info