perf: add AliasResolver caching and use batch saves consistently

[Soner (shyim)]

Summary

• Add resolve cache to AliasResolver to avoid repeated string concatenation when resolving the same type multiple times
• Convert remaining indexers to use BatchSaveItems for consistency and reduced transaction overhead

Changes

AliasResolver Caching (alias_resolver.go)

• Added resolveCache map to cache resolved type names
• First lookup resolves and caches, subsequent lookups return cached value
• Avoids repeated string concatenation (namespace + "\\" + typeName)

Batch Saves

• TwigIndexer: Convert SaveItem to BatchSaveItems for twig files
• ExtensionIndexer: Convert both indexBundle and indexApp to use BatchSaveItems

Benchmark Results

BenchmarkResolveType-16            	 9838870	       117.9 ns/op	       0 B/op	       0 allocs/op
BenchmarkResolveTypeRepeated-16    	100000000	        10.36 ns/op	       0 B/op	       0 allocs/op

Cache hits are ~11x faster than the mixed workload (10ns vs 117ns), with 0 allocations.

Testing

go test ./...
golangci-lint run

All tests pass, no lint issues.