fix(build): drop redundant tui->deepseek shim binary (Windows LNK1104)

5770a574 added crates/tui/src/bin/deepseek.rs as a shim that calls
deepseek_tui_cli::run_cli() so `cargo install deepseek-tui` would also
install the canonical `deepseek` command. But the cli crate already
declares an identically-named bin target, so workspace builds emit two
artifacts to target/release/deepseek(.exe) -- cargo prints `output
filename collision` and on Windows the second linker hits LNK1104:
cannot open file deepseek.exe (the first hold has not released).

The cli crate stays the single source of `deepseek`. Workspace default
members still produce both binaries (deepseek from cli, deepseek-tui
from tui), no collision. Cargo install path: `cargo install
deepseek-tui-cli` for the canonical `deepseek` command, `cargo install
deepseek-tui` for the TUI binary; npm wrapper unaffected.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

crates/tui/Cargo.toml

@@ -11,11 +11,6 @@ default-run = "deepseek-tui"
 name = "deepseek-tui"
 path = "src/main.rs"
 
-[[bin]]
-name = "deepseek"
-path = "src/bin/deepseek.rs"
-doc = false
-
 [dependencies]
 anyhow = "1.0.100"
 arboard = "3.4"

crates/tui/src/bin/deepseek.rs

@@ -1,3 +0,0 @@
-fn main() -> std::process::ExitCode {
-    deepseek_tui_cli::run_cli()
-}