refactor: consolidate nvim crates, extract server library, and update workspace dependencies

server/Cargo.toml

@@ -3,6 +3,10 @@ name = "mcp-memory-server"
 version = "1.0.0"
 edition = "2024"
 
+[lib]
+name = "mcp_memory_server"
+path = "src/lib.rs"
+
 [dependencies]
 async-trait = "0.1.92"
 axum = { version = "0.8", features = ["ws"] }
@@ -50,10 +54,4 @@ winres = "0.1.12"
 [dev-dependencies]
 tempfile = "3.27.0"
 
-[[bin]]
-name = "bin_clipboard_test"
-path = "src/bin_clipboard_test.rs"
 
-[[bin]]
-name = "test_clip_write"
-path = "src/test_clip_write.rs"