feat(llm): add kon-llm crate with llama-cpp-2 inference, model management, and Tauri commands

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

crates/llm/Cargo.toml

@@ -0,0 +1,15 @@
+[package]
+name = "kon-llm"
+version = "0.1.0"
+edition = "2021"
+description = "Local LLM inference via llama.cpp for Kon"
+
+[dependencies]
+kon-core = { path = "../core" }
+llama-cpp-2 = "0.1"
+tokio = { version = "1", features = ["rt", "sync"] }
+reqwest = { version = "0.12", features = ["stream"] }
+futures-util = "0.3"
+serde = { version = "1", features = ["derive"] }
+serde_json = "1"
+log = "0.4"