Extend extraction to index two additional categories of symbols
that were previously invisible:
1. Type aliases (e.g. `export type X = ...` in TypeScript,
`type X` in Go, `type X = ...` in Rust, `typealias X` in Swift,
`type_alias` in Kotlin). Adds `typeAliasTypes` to the
LanguageExtractor interface with values for all 13 languages.
2. Exported variable declarations that aren't functions, including:
- Zustand stores: `export const useX = create(...)`
- XState machines: `export const xMachine = createMachine(...)`
- Zod schemas: `export const schema = z.object(...)`
- Config objects: `export const config = { ... }`
- Constants: `export const MAX = 3`
- Arrays: `export const NAMES = [...] as const`
The extractExportedVariables() method is called when visiting
export_statement nodes. It skips variable_declarator values that
are already handled by functionTypes (arrow_function,
function_expression) to avoid duplicate extraction.
Adds 11 new test cases (59 total extraction tests, 215 total).
Tested on production monorepo: nodes increased from 958 to 1,172
(+22%), with 109 new variable nodes and 105 new type_alias nodes.
Only 4 files remain at 0 nodes — all are re-export barrels or
ambient declaration files with no extractable symbols.