feat: Language expansion — 6 → 15+ language support

[ajianaz]

Description

Expand language-specific analysis from 6 to 15+ languages.

Currently supported: Dart/Flutter, Svelte, TypeScript, Go, Rust, Python

Add: Java, C#, C/C++, Kotlin, Ruby, PHP, Swift, Scala, Lua, Zig

Why

CodeGraph supports 30+ languages. Graphify supports 20+. For code intelligence to be credible, Cora needs broader language coverage. Each language needs:

• AST-aware analysis patterns
• Language-specific rule presets in .cora.yaml
• Symbol extraction grammar for the index

Scope

• Language detection and routing in analyzers
• Per-language rule presets
• AST grammar support for new languages
• Test coverage per language (measure cross-file accuracy like CodeGraph does)

Depends On

• feat: cora index — Symbol index & SQLite persistence #264 cora index (symbol extraction per language)

Strategy Ref

Code intelligence strategy #5 from competitive analysis.