nixvim: improve keymaps, completion, and formatter config

- Add LSP code actions, diagnostic navigation, window navigation keymaps
- Move telescope keymaps to explicit mkRaw form for reliability
- Change buffer nav from <leader>bh/bl to [b/]b
- Fix conform double-setup by moving config to native nixvim settings
- Fix <leader>cf to use conform instead of vim.lsp.buf.format
- Fix <leader>ca to pass diagnostic context to code_action
- Add nvim-lightbulb for code action indicator
- Configure copilot Tab conflict: blink-cmp Tab=accept, C-n/p for cycling
- Add completion.list.selection preselect for immediate Tab acceptance
- Add TypeScript Japanese locale for LSP diagnostics

Co-Authored-By: Claude Sonnet 4.6 <[email protected]>

modules/home/nixvim/plugins/editor/blink-cmp.nix

@@ -12,8 +12,29 @@
         "<C-e>" = ["hide"];
         "<C-f>" = ["scroll_documentation_down"];
 
-        "<Tab>" = ["select_next" "fallback"];
+        "<Tab>" = [
+          "accept"
+          {
+            __raw = ''
+              function()
+                local ok, copilot = pcall(require, "copilot.suggestion")
+                if ok and copilot.is_visible() then
+                  copilot.accept()
+                  return true
+                end
+              end
+            '';
+          }
+          "fallback"
+        ];
         "<S-Tab>" = ["select_prev" "fallback"];
+        "<C-n>" = ["select_next" "fallback"];
+        "<C-p>" = ["select_prev" "fallback"];
+      };
+
+      completion.list.selection = {
+        preselect = true;
+        auto_insert = false;
       };
 
       sources.default = [

modules/home/nixvim/plugins/editor/conform.nix

@@ -1,3 +1,24 @@
 {...}: {
-  programs.nixvim.plugins."conform-nvim".enable = true;
+  programs.nixvim.plugins."conform-nvim" = {
+    enable = true;
+    settings = {
+      formatters_by_ft = {
+        javascript.__raw = ''{ "prettierd", "prettier", stop_after_first = true }'';
+        javascriptreact.__raw = ''{ "prettierd", "prettier", stop_after_first = true }'';
+        typescript.__raw = ''{ "prettierd", "prettier", stop_after_first = true }'';
+        typescriptreact.__raw = ''{ "prettierd", "prettier", stop_after_first = true }'';
+        json.__raw = ''{ "prettierd", "prettier", stop_after_first = true }'';
+        yaml.__raw = ''{ "prettierd", "prettier", stop_after_first = true }'';
+        markdown.__raw = ''{ "prettierd", "prettier", stop_after_first = true }'';
+        lua = ["stylua"];
+        nix = ["alejandra"];
+        sh = ["shfmt"];
+      };
+      format_on_save.__raw = ''
+        function(_)
+          return { timeout_ms = 1000, lsp_format = "fallback" }
+        end
+      '';
+    };
+  };
 }

modules/home/nixvim/plugins/editor/copilot.nix

@@ -1,5 +1,11 @@
 {...}: {
   programs.nixvim.plugins.copilot-lua = {
     enable = true;
+    settings = {
+      suggestion = {
+        auto_trigger = true;
+        keymap.enabled = false;
+      };
+    };
   };
 }

modules/home/nixvim/plugins/editor/telescope.nix

@@ -1,43 +1,6 @@
 {...}: {
-  programs.nixvim = {
-    plugins.telescope = {
-      enable = true;
-      extensions = {
-        fzf-native.enable = true;
-      };
-      keymaps = {
-        "<leader>ff" = {
-          action = "find_files";
-          options = {
-            desc = "ファイルを探す";
-            silent = true;
-          };
-        };
-
-        "<leader>fg" = {
-          action = "live_grep";
-          options = {
-            desc = "文字列を全文検索";
-            silent = true;
-          };
-        };
-
-        "<leader>fb" = {
-          action = "buffers";
-          options = {
-            desc = "開いているバッファを探す";
-            silent = true;
-          };
-        };
-
-        "<leader>fh" = {
-          action = "help_tags";
-          options = {
-            desc = "ヘルプ項目を探す";
-            silent = true;
-          };
-        };
-      };
-    };
+  programs.nixvim.plugins.telescope = {
+    enable = true;
+    extensions.fzf-native.enable = true;
   };
 }

modules/home/nixvim/plugins/ui/default.nix

@@ -8,5 +8,6 @@
     ./toggleterm.nix
     ./treesitter.nix
     ./barbar.nix
+    ./lightbulb.nix
   ];
 }

modules/home/nixvim/plugins/ui/lightbulb.nix

@@ -0,0 +1,6 @@
+{...}: {
+  programs.nixvim.plugins.nvim-lightbulb = {
+    enable = true;
+    settings.autocmd.enabled = true;
+  };
+}