feat: initial blink-cmp-ssh implementation

Problem: the existing blink-cmp-sshconfig plugin uses a synchronous,
build-time Python scraping approach that requires uv and make to
generate a static Lua file.

Solution: implement a runtime, async blink.cmp source that parses
ssh_config keywords from man ssh_config and enum values from ssh -Q
queries, matching the architecture of blink-cmp-tmux and
blink-cmp-ghostty.

.editorconfig

@@ -0,0 +1,9 @@
+root = true
+
+[*]
+insert_final_newline = true
+charset = utf-8
+
+[*.lua]
+indent_style = space
+indent_size = 2