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.

.github/workflows/test.yaml

@@ -0,0 +1,22 @@
+name: test
+
+on:
+  pull_request:
+    branches: [main]
+  push:
+    branches: [main]
+
+jobs:
+  test:
+    runs-on: ubuntu-latest
+    strategy:
+      fail-fast: false
+      matrix:
+        nvim: [stable, nightly]
+    name: Test (Neovim ${{ matrix.nvim }})
+    steps:
+      - uses: actions/checkout@v4
+
+      - uses: nvim-neorocks/nvim-busted-action@v1
+        with:
+          nvim_version: ${{ matrix.nvim }}