Update naming conventions in .editorconfig and docs.editorc

backend/.editorconfig

@@ -33,28 +33,37 @@ csharp_style_prefer_primary_constructors = true:suggestion
 csharp_style_expression_bodied_methods = when_on_single_line:suggestion
 dotnet_style_prefer_collection_expression = when_types_loosely_match:suggestion
 
+# Naming. Roslyn applies the first matching rule in file order, so the specific rules come first.
+# Private fields are _camelCase whatever their modifiers (static, readonly, const).
 dotnet_naming_rule.private_fields.symbols = private_fields
-dotnet_naming_rule.private_fields.style = camel_case
+dotnet_naming_rule.private_fields.style = underscore_camel_case
 dotnet_naming_rule.private_fields.severity = warning
 dotnet_naming_symbols.private_fields.applicable_kinds = field
 dotnet_naming_symbols.private_fields.applicable_accessibilities = private
-dotnet_naming_symbols.private_fields.required_modifiers =
-dotnet_naming_style.camel_case.capitalization = camel_case
+dotnet_naming_style.underscore_camel_case.capitalization = camel_case
+dotnet_naming_style.underscore_camel_case.required_prefix = _
 
-dotnet_naming_rule.private_static_readonly.symbols = private_static_readonly
-dotnet_naming_rule.private_static_readonly.style = pascal_case
-dotnet_naming_rule.private_static_readonly.severity = warning
-dotnet_naming_symbols.private_static_readonly.applicable_kinds = field
-dotnet_naming_symbols.private_static_readonly.applicable_accessibilities = private
-dotnet_naming_symbols.private_static_readonly.required_modifiers = static, readonly
-
-dotnet_naming_rule.private_constants.symbols = private_constants
-dotnet_naming_rule.private_constants.style = pascal_case
-dotnet_naming_rule.private_constants.severity = warning
-dotnet_naming_symbols.private_constants.applicable_kinds = field
-dotnet_naming_symbols.private_constants.required_modifiers = const
+# Non-private fields (constants, static readonly, etc.) are PascalCase.
+dotnet_naming_rule.other_fields.symbols = other_fields
+dotnet_naming_rule.other_fields.style = pascal_case
+dotnet_naming_rule.other_fields.severity = warning
+dotnet_naming_symbols.other_fields.applicable_kinds = field
+dotnet_naming_symbols.other_fields.applicable_accessibilities = public, internal, protected, protected_internal, private_protected
 dotnet_naming_style.pascal_case.capitalization = pascal_case
 
+dotnet_naming_rule.interfaces.symbols = interfaces
+dotnet_naming_rule.interfaces.style = interface_style
+dotnet_naming_rule.interfaces.severity = warning
+dotnet_naming_symbols.interfaces.applicable_kinds = interface
+dotnet_naming_style.interface_style.capitalization = pascal_case
+dotnet_naming_style.interface_style.required_prefix = I
+
+dotnet_naming_rule.types_and_members.symbols = types_and_members
+dotnet_naming_rule.types_and_members.style = pascal_case
+dotnet_naming_rule.types_and_members.severity = warning
+dotnet_naming_symbols.types_and_members.applicable_kinds = class, struct, enum, delegate, property, method, event
+dotnet_naming_symbols.types_and_members.applicable_accessibilities = *
+
 # CA1848/CA1873 would turn every log call into a [LoggerMessage] source-generated method; CA1716 flags the
 # EF-style IDatabase.Set<T>() and the Musify.Application.Shared namespace, whose names are deliberate.
 dotnet_diagnostic.CA1848.severity = suggestion

backend/CLAUDE.md

@@ -20,7 +20,7 @@ dotnet format Musify.slnx --verify-no-changes
 ## Style
 
 - Block-scoped namespaces (`namespace X { }`; file-scoped `namespace X;` is not allowed), usings outside the namespace and sorted (`.editorconfig` enforces it).
-- Private fields camelCase without underscore, constants and `static readonly` fields PascalCase, explicit accessibility.
+- Private fields are `_camelCase` whatever their modifiers (including `static readonly` and `const`); non-private constants and static fields, types, methods and properties are PascalCase; interfaces start with `I`; explicit accessibility. Enforced by `.editorconfig` (IDE1006).
 - `ArgumentNullException.ThrowIfNull(x)` without `nameof`.
 - Use `PlayList` (not `Playlist`) in code; configuration POCOs end in `Configuration`; injected services are named after their type (`storageService`).
 - User-facing strings are in English (the web-player owns translation).