feat(plugins): add Blink supermaven, external TUI, and heirline statusline plugins

lua/plugins/external-tui.lua

@@ -0,0 +1,30 @@
+--- External TUIs without a dedicated snacks.nvim integration (nvim-external-tui).
+--- Tools that DO have a native snacks path (lazygit -> Snacks.lazygit,
+--- lazydocker -> Snacks.terminal) are wired directly in astrocore.lua.
+---@type LazySpec
+return {
+  "gfontenot/nvim-external-tui",
+  dependencies = { "folke/snacks.nvim" },
+  event = "VeryLazy",
+  config = function()
+    local external_tui = require "external-tui"
+
+    external_tui.setup {
+      -- the `scooter` win style (snacks opts.styles in user.lua) renders the
+      -- terminal as a borderless right-hand 30% split
+      terminal_provider = {
+        snacks = { win = { style = "scooter" } },
+      },
+    }
+
+    -- :Scooter — find & replace TUI; picking a result closes the terminal
+    -- and opens the file at that line in this nvim instance. Visual range
+    -- (:'<,'>Scooter) and args (:Scooter term) prefill the search text.
+    external_tui.add {
+      user_cmd = "Scooter",
+      cmd = "scooter",
+      text_flag = "--search-text",
+      editor_flag = "--editor-command", -- scooter >= 0.8.4
+    }
+  end,
+}