feat: allow custom input provider, removing dressing.nvim (#2173)

Co-authored-by: pre-commit-ci-lite[bot] <117423508+pre-commit-ci-lite[bot]@users.noreply.github.com>
Co-authored-by: yetone <yetoneful@gmail.com>

lua/avante/health.lua

@@ -12,10 +12,6 @@ function M.check()
       path = "nvim-treesitter/nvim-treesitter",
       module = "nvim-treesitter",
     },
-    ["dressing.nvim"] = {
-      path = "stevearc/dressing.nvim",
-      module = "dressing",
-    },
     ["plenary.nvim"] = {
       path = "nvim-lua/plenary.nvim",
       module = "plenary",
@@ -41,6 +37,24 @@ function M.check()
     H.warn("No icons plugin found (nvim-web-devicons or mini.icons). Icons will not be displayed")
   end
 
+  -- Check input UI provider
+  local input_provider = Config.input and Config.input.provider or "native"
+  if input_provider == "dressing" then
+    if Utils.has("dressing.nvim") or Utils.has("dressing") then
+      H.ok("Found configured input provider: dressing.nvim")
+    else
+      H.error("Input provider is set to 'dressing' but dressing.nvim is not installed")
+    end
+  elseif input_provider == "snacks" then
+    if Utils.has("snacks.nvim") or Utils.has("snacks") then
+      H.ok("Found configured input provider: snacks.nvim")
+    else
+      H.error("Input provider is set to 'snacks' but snacks.nvim is not installed")
+    end
+  else
+    H.ok("Using native input provider (no additional dependencies required)")
+  end
+
   -- Check Copilot if configured
   if Config.provider and Config.provider == "copilot" then
     if Utils.has("copilot.lua") or Utils.has("copilot.vim") or Utils.has("copilot") then