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.

spec/minimal_init.lua

@@ -0,0 +1,34 @@
+vim.cmd([[set runtimepath=$VIMRUNTIME]])
+vim.opt.runtimepath:append('.')
+vim.opt.packpath = {}
+vim.opt.loadplugins = false
+
+package.loaded['blink.cmp.types'] = {
+  CompletionItemKind = {
+    Text = 1,
+    Method = 2,
+    Function = 3,
+    Constructor = 4,
+    Field = 5,
+    Variable = 6,
+    Class = 7,
+    Interface = 8,
+    Module = 9,
+    Property = 10,
+    Unit = 11,
+    Value = 12,
+    Enum = 13,
+    Keyword = 14,
+    Snippet = 15,
+    Color = 16,
+    File = 17,
+    Reference = 18,
+    Folder = 19,
+    EnumMember = 20,
+    Constant = 21,
+    Struct = 22,
+    Event = 23,
+    Operator = 24,
+    TypeParameter = 25,
+  },
+}