Story 18: Token-by-token streaming responses

- Backend: Added OllamaProvider::chat_stream() with newline-delimited JSON parsing
- Backend: Emit chat:token events for each token received from Ollama
- Backend: Added futures dependency and stream feature for reqwest
- Frontend: Added streamingContent state and chat:token event listener
- Frontend: Real-time token display with auto-scroll
- Frontend: Markdown and syntax highlighting support for streaming content
- Fixed all TypeScript errors (tsc --noEmit)
- Fixed all Biome warnings and errors
- Fixed all Clippy warnings
- Added comprehensive code quality documentation
- Added tsc --noEmit to verification checklist

Tested and verified:
- Tokens stream in real-time
- Auto-scroll works during streaming
- Tool calls interrupt streaming correctly
- Multi-turn conversations work
- Smooth performance with no lag

src-tauri/Cargo.toml

@@ -25,10 +25,9 @@ serde_json = "1"
 tauri-plugin-dialog = "2.4.2"
 ignore = "0.4.25"
 walkdir = "2.5.0"
-reqwest = { version = "0.12.28", features = ["json", "blocking"] }
+reqwest = { version = "0.12.28", features = ["json", "blocking", "stream"] }
+futures = "0.3"
 uuid = { version = "1.19.0", features = ["v4", "serde"] }
 chrono = { version = "0.4.42", features = ["serde"] }
 async-trait = "0.1.89"
 tauri-plugin-store = "2.4.1"
-tokio = { version = "1.48.0", features = ["sync"] }
-