Add resource_name variable to template context

[jeffreyaven]

Summary

This change enables templates to reference the current resource's name via a resource_name variable, similar to existing stack_name and stack_env variables. This allows global context values (like tags) to be customized per-resource using template expressions.

Key Changes

• Added resource_name injection: The get_full_context() function now injects resource_name into the context before rendering resource properties
• Implemented deferred variable resolution: New re_render_context_with_deferred_vars() function re-renders global context values that contain template expressions (e.g., {{ resource_name }}), allowing globals defined at startup to reference resource-specific variables
• Updated context flow: Global context is now re-rendered with the resource name available, ensuring that deferred template expressions in globals are properly resolved before being merged with resource properties
• Added comprehensive tests: Six new test cases covering:
  • resource_name availability in full context
  • resource_name usage in resource properties
  • Resolution of deferred globals containing {{ resource_name }}
  • Per-resource variation of resource_name
  • No-op behavior when no templates are present
  • Deferred variable resolution in context

Implementation Details

• The resource_name variable is injected into a cloned copy of the global context before property rendering
• Deferred variables are identified by checking for {{ in values and are re-rendered using the template engine
• Boolean values are normalized (Python's True/False → JSON's true/false) during re-rendering
• Failed re-renders log a debug warning but don't break the flow
• All existing context variables remain available and unchanged

https://claude.ai/code/session_01JVr4F97rZNWMEsADMpAotd