Inline inspector locals and tidy up comments

Replace `inspector` local variables with direct `@inspectors[object]`
calls throughout InterfaceChecker. Consolidate ParamsNormalizer's
class-level and inline comments into a single class-level comment,
and rename `non_keywords` to `sequentials` for consistency with
`SEQUENTIAL_TYPES`. Add `params` naming convention to CLAUDE.md.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

Author: thiagoa

CLAUDE.md

@@ -42,3 +42,5 @@
 - Extract constants for inline literals used in conditionals.
 - Private methods mirror each other when they share a common role
   (e.g. `sort_keyword_params` / `sequentialize_params`).
+- Use `params` instead of `parameters` in names (e.g. method names,
+  variable names).

lib/duck_typer/interface_checker.rb

@@ -32,11 +32,10 @@ def calculate_diff(left, right)
     end
 
     def params_for_comparison(object, params_processor)
-      inspector = @inspectors[object]
-      methods = @partial_interface_methods || inspector.public_methods
+      methods = @partial_interface_methods || @inspectors[object].public_methods
 
       methods.map do |method_name|
-        params = method_params(inspector, method_name, object)
+        params = method_params(method_name, object)
         args = params_processor.call(params).map do |type, name|
           case type
           when :key then "#{name}: :opt"
@@ -54,8 +53,8 @@ def params_for_comparison(object, params_processor)
       end
     end
 
-    def method_params(inspector, method_name, object)
-      inspector.parameters_for(method_name)
+    def method_params(method_name, object)
+      @inspectors[object].parameters_for(method_name)
     rescue NameError
       raise MethodNotFoundError, "undefined method `#{method_name}' for #{object}"
     end
@@ -74,8 +73,7 @@ def diff_message(left, right, diff)
     end
 
     def join_signature(object, method_name, all_params)
-      inspector = @inspectors[object]
-      display_name = inspector.display_name_for(method_name)
+      display_name = @inspectors[object].display_name_for(method_name)
       method_params = all_params.assoc(method_name)&.last
 
       signature = if method_params

lib/duck_typer/params_normalizer.rb

@@ -1,12 +1,11 @@
 # frozen_string_literal: true
 
 module DuckTyper
-  # Normalizes method parameters to enable interface comparison. For
-  # example, two methods may use different names for positional
-  # arguments, but if the parameter types and order match, they should
-  # be considered equivalent. This class replaces argument names with
-  # sequential placeholders when appropriate, focusing the comparison on
-  # parameter structure rather than naming.
+  # Normalizes method parameters to enable interface comparison.
+  # Keyword argument order is irrelevant — m(a:, b:) and m(b:, a:)
+  # are equivalent — so keywords are sorted alphabetically. Positional
+  # argument names are also replaced with sequential placeholders,
+  # focusing the comparison on parameter structure rather than naming.
   class ParamsNormalizer
     KEYWORD_TYPES = %i[key keyreq].freeze
     SEQUENTIAL_TYPES = %i[req opt rest keyrest block].freeze
@@ -18,15 +17,12 @@ def call(params)
 
       private
 
-      # Keyword argument order is irrelevant to a method's interface —
-      # m(a:, b:) and m(b:, a:) are equivalent. Sort keyword params
-      # alphabetically so comparison is order-independent.
       def sort_keyword_params(params)
-        keywords, non_keywords = params.partition do |type, _|
+        keywords, sequentials = params.partition do |type, _|
           KEYWORD_TYPES.include?(type)
         end
 
-        non_keywords + keywords.sort_by { |_, name| name }
+        sequentials + keywords.sort_by { |_, name| name }
       end
 
       def sequentialize_params(params)