fix: resolve test failures and complete diff keymap refactor

Fixes #44 - test failures were caused by missing vim.b mock in test environment.

Changes:
- Add vim.b metatable mock to handle buffer-local variables in tests
- Update dev config diff keymaps to avoid conflicts (<leader>aa/<leader>ad)
- Remove outdated keymap comments from diff.lua
- Fix minor formatting issues in README.md

Tests now pass: 278 successes / 0 failures / 0 errors

Change-Id: I3af59441d9940869e3ed0f7566a09892908bd16b
Signed-off-by: Thomas Kosiewski <tk@coder.com>

Author: ThomasK33

README.md

@@ -170,11 +170,11 @@ The diff keymaps are configured in the LazyVim spec and can be customized by mod
   config = true,
   keys = {
     -- ... other keymaps ...
-    
+
     -- Customize diff keymaps to avoid conflicts (e.g., with debugger)
     { "<leader>ya", "<cmd>ClaudeCodeDiffAccept<cr>", desc = "Accept diff" },
     { "<leader>yn", "<cmd>ClaudeCodeDiffDeny<cr>", desc = "Deny diff" },
-    
+
     -- Or disable them entirely by omitting them from the keys table
   },
 }

dev-config.lua

@@ -33,8 +33,8 @@ return {
     { "<leader>aQ", "<cmd>ClaudeCodeStop<cr>", desc = "Stop Claude Server" },
 
     -- Diff management (buffer-local, only active in diff buffers)
-    { "<leader>da", "<cmd>ClaudeCodeDiffAccept<cr>", desc = "Accept diff" },
-    { "<leader>dq", "<cmd>ClaudeCodeDiffDeny<cr>", desc = "Deny diff" },
+    { "<leader>aa", "<cmd>ClaudeCodeDiffAccept<cr>", desc = "Accept diff" },
+    { "<leader>ad", "<cmd>ClaudeCodeDiffDeny<cr>", desc = "Deny diff" },
   },
 
   -- Development configuration - all options shown with defaults commented out

lua/claudecode/diff.lua

@@ -583,11 +583,6 @@ function M._create_diff_view_from_window(target_window, old_file_path, new_buffe
   vim.b[new_buffer].claudecode_diff_new_win = new_win
   vim.b[new_buffer].claudecode_diff_target_win = target_window
 
-  -- Note: Keymaps for diff accept/deny are now configured in the LazyVim spec
-  -- Users can customize them by adding to their plugin configuration:
-  -- { "<leader>da", "<cmd>ClaudeCodeDiffAccept<cr>", desc = "Accept diff", buffer = true }
-  -- { "<leader>dq", "<cmd>ClaudeCodeDiffDeny<cr>", desc = "Deny diff", buffer = true }
-
   -- Return window information for later storage
   return {
     new_window = new_win,

tests/mocks/vim.lua

@@ -582,6 +582,25 @@ local vim = {
     end,
   }),
 
+  b = setmetatable({}, {
+    __index = function(_, bufnr)
+      -- Return buffer-local variables for the given buffer
+      if vim._buffers[bufnr] then
+        if not vim._buffers[bufnr].b_vars then
+          vim._buffers[bufnr].b_vars = {}
+        end
+        return vim._buffers[bufnr].b_vars
+      end
+      return {}
+    end,
+    __newindex = function(_, bufnr, vars)
+      -- Set buffer-local variables for the given buffer
+      if vim._buffers[bufnr] then
+        vim._buffers[bufnr].b_vars = vars
+      end
+    end,
+  }),
+
   deepcopy = function(tbl)
     if type(tbl) ~= "table" then
       return tbl