Add Metadata.Context completion, hover, and quick fix

[satyakigh]

Summary

Add first-class editor support for CloudFormation com.aws.cloudformation.Context metadata.

• Add schema-aware completion for:
• Template fields: arch, must, ref, and owner
• Resource fields: why, must, mutable, mutability, trust, and deps
• Nested ref and trust structures
• Mutability, trust-source, and confidence enum values
• Add hover documentation with field types, required fields, enum values, advisory-schema guidance, and links to the authoritative AWS documentation.
• Add a quick fix that inserts template- or resource-level Context skeletons in response to missing-context diagnostics.
• Support YAML and JSON while preserving existing arbitrary Metadata entries.
• Support recoverable malformed templates, including partial keys, missing JSON closing braces, and valid islands following unrelated syntax errors.
• Preserve existing behavior at wholly invalid positions and avoid offering CodeActions when a safe insertion point cannot be resolved.

The shared Metadata Context schema uses the existing PropertyType convention under src/schema. No LSP protocol or client changes are required.

Documentation: https://docs.aws.amazon.com/AWSCloudFormation/latest/TemplateReference/aws-attribute-metadata.html#aws-attribute-metadata-context-schema

Implementation notes

Malformed JSON path recovery now:

• Runs only when the cursor has a local tree-sitter ERROR ancestor
• Preserves normal ancestor and entity context
• Merges normal and fallback property paths only when they overlap
• Distinguishes partial object keys from scalar values
• Handles UTF-8 tree-sitter columns without copying the full document

[github-code-quality]

Code Coverage Overview

Languages: TypeScript

TypeScript / code-coverage/vitest

The overall line coverage in commit 5cd82fd in the context branch remains at 90%, unchanged from commit 6ec8eee in the main branch.

Show a line coverage summary of the most impacted files.

File	main 6ec8eee	context 5cd82fd	+/-
src/autocomplet...letionRouter.ts	90%	90%	0%
src/services/Co...ctionService.ts	76%	77%	+1%
src/hover/HoverRouter.ts	89%	90%	+1%
src/document/Document.ts	98%	100%	+2%
src/context/syn...e/SyntaxTree.ts	92%	97%	+5%
src/services/Me...textQuickFix.ts	0%	93%	+93%
src/autocomplet...tionProvider.ts	0%	93%	+93%
src/schema/Meta...ontextSchema.ts	0%	93%	+93%
src/hover/Metad...overProvider.ts	0%	95%	+95%
src/context/MetadataContext.ts	0%	100%	+100%

---

_{Updated September 08, 2026 17:30 UTC}

[satyakigh]

.