Add diagnostic kill switch to VS Code and GoLand extensions

[willibrandon]

Problem

Users currently have no convenient way to temporarily disable mtlog-analyzer diagnostics when they become disruptive. This can lead to frustration and potentially users disabling or uninstalling the extensions entirely.

Proposed Solution

Add a quick and discoverable "kill switch" to both the VS Code extension and GoLand plugin that allows users to:

1. Quickly disable all mtlog diagnostics with a single action
2. Easily re-enable them when ready
3. See the current state (enabled/disabled)

VS Code Implementation

• Add command palette commands: "mtlog: Disable all diagnostics" / "mtlog: Enable diagnostics"
• Add status bar item showing state (e.g., "mtlog ✓" or "mtlog ✗") that's clickable to toggle
• Add quick action on any diagnostic: "Disable all mtlog diagnostics"
• Persist state in workspace settings

GoLand Implementation

• Add intention action: "Disable all mtlog inspections"
• Add notification bar when active: "mtlog analyzer is active [Disable] [Settings]"
• Add status bar widget to toggle on/off
• Respect IntelliJ's standard inspection suppression mechanisms

Acceptance Criteria

• Users can disable all diagnostics with 2 clicks or less
• The disabled state is clearly visible
• Re-enabling is just as easy as disabling
• Settings persist across IDE restarts
• No loss of user configuration when toggling

Why This Matters

Even the best static analysis tools need an escape hatch. Users might need to temporarily disable diagnostics when:

• Working on legacy code
• Dealing with tight deadlines
• Debugging unrelated issues
• The analyzer has a bug causing false positives

Without this feature, frustrated users might permanently uninstall the extensions instead of just temporarily disabling them.