fix(nvim): enable yaml syntax highlighting for sops files

Add BufReadPre autocmd to set filetype=yaml before buffer is loaded,
ensuring syntax highlighting works immediately when opening encrypted
sops files. Also updated BufReadPost to unconditionally set yaml
filetype after decryption.

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude <noreply@anthropic.com>

hosts/nb/modules/development/nvim/config/sops.lua

@@ -19,6 +19,16 @@ local function is_secrets_file(filepath)
   return false
 end
 
+-- Set filetype before reading to enable syntax highlighting
+vim.api.nvim_create_autocmd("BufReadPre", {
+  group = sops_group,
+  pattern = secrets_patterns,
+  callback = function(args)
+    -- Set filetype to yaml before the file is read so syntax highlighting works
+    vim.bo.filetype = "yaml"
+  end,
+})
+
 -- Decrypt file after reading
 vim.api.nvim_create_autocmd("BufReadPost", {
   group = sops_group,
@@ -50,10 +60,8 @@ vim.api.nvim_create_autocmd("BufReadPost", {
         vim.bo.writebackup = false
         vim.bo.undofile = false
 
-        -- Set filetype to yaml if not already set
-        if vim.bo.filetype == "" then
+        -- Ensure filetype is set to yaml for syntax highlighting
         vim.bo.filetype = "yaml"
-        end
 
         vim.notify("SOPS: File decrypted successfully", vim.log.levels.INFO)
       else