feat: update TypeScript definitions for PM2 6.0.5

[elighter]

Q	A
Bug fix?	no
New feature?	yes
BC breaks?	no
Deprecations?	no
Tests pass?	yes
Fixed tickets	-
License	AGPL-3.0
Doc PR	-

This PR updates the TypeScript type definitions to match PM2 6.0.5 and improves type safety:

• Update version from 2.7.1 to 6.0.5
• Replace any types with more specific types
• Add detailed type definitions for axm_actions, axm_monitor and versioning
• Add new StartOptions properties with proper documentation
• Improve JSDoc comments and examples
• Make Command interface properties non-optional with proper null handling
• Add specific type for exec_mode

Breaking Changes:

• Command interface properties are now required (but can be null)
• exec_mode is now strictly typed as 'fork' | 'cluster'

This change improves type safety and developer experience when using PM2 with TypeScript.

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