docs: add guideline to avoid Rust keywords as field names

Added explicit rules to both CLAUDE.md and CONTRIBUTING.md prohibiting the use of Rust keywords (type, use, trait, impl, etc.) as struct field names, especially in public APIs.

Problem: Rust keywords require the r# prefix (e.g., r#type), which causes serialization inconsistencies across language bindings:
- Polkadot.js converts to r_type or rType
- Serde serializes as type
- Creates confusion and breaks API consistency

Solution: Use alternative names like kind, variant, scope, category, or mode instead. This guideline applies to all public structs, especially those in api crates and types exposed to external clients.

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

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

Author: steinerkelvin

CLAUDE.md

@@ -26,16 +26,19 @@ Torus is a stake-driven peer-to-peer network built on Substrate. The blockchain
 The `permission0` pallet manages delegated permissions and access control within the Torus network. Key components:
 
 **Core Permission Types** (`pallets/permission0/src/permission.rs`):
+
 - `PermissionContract<T>` - Main permission structure with delegator, recipient, scope, duration, and enforcement
 - `PermissionId` - Unique permission identifier (H256 hash)
 - `PermissionScope<T>` - Defines what actions the permission covers
 - `NamespaceScope<T>` - Defines namespace path permissions for delegation
 
 **Permission Scopes** (`pallets/permission0/src/permission/`):
+
 - `pallets/permission0/src/permission/curator.rs` - `CuratorPermissions` and `CuratorScope` types
 - `pallets/permission0/src/permission/emission.rs` - `EmissionAllocation`, `DistributionControl`, and `EmissionScope` types
 
 **Implementation Handlers** (`pallets/permission0/src/ext/`):
+
 - `pallets/permission0/src/ext/curator_impl.rs` - Functions for curator permission enforcement
 - `pallets/permission0/src/ext/emission_impl.rs` - Functions for emission permission enforcement  
 - `pallets/permission0/src/ext/namespace_impl.rs` - Functions for namespace permission enforcement
@@ -77,6 +80,7 @@ cargo build --release                # Build the node
 - **MUST ALWAYS** use `ensure!` macro for validation, NEVER `assert!`
 - **MUST ALWAYS** use the `?` operator for error propagation
 - **MUST ALWAYS** use pattern matching with proper error handling:
+
   ```rust
   let Some(value) = some_option else {
       return Err(Error::<T>::SomeError.into());
@@ -132,17 +136,32 @@ cargo build --release                # Build the node
 - **MUST ALWAYS** use proper type conversions with `.try_into()` and handle errors
 - **MUST NEVER** use `as` for lossy numeric conversions
 
+### API Design - MANDATORY
+
+- **MUST NEVER** use Rust keywords as struct field names (e.g., `type`, `use`, `trait`, `impl`)
+- **PROBLEM**: Rust keywords require `r#` prefix (e.g., `r#type`), causing serialization inconsistencies:
+  - Polkadot.js converts to `r_type` or `rType`
+  - Serde serializes as `type`
+  - Creates confusion and breaks API consistency across language bindings
+- **MUST ALWAYS** use alternative names: `kind`, `variant`, `scope`, `category`, `mode`, etc.
+- **APPLIES TO**: All public structs, especially those in `api` crates and types exposed to external clients
+
 ### Common Code Patterns - REQUIRED
 
 - **MUST ALWAYS** emit events after successful state changes:
+
   ```rust
   Pallet::<T>::deposit_event(Event::<T>::SomethingHappened(who, what));
   ```
+
 - **MUST ALWAYS** validate string data is UTF-8:
+
   ```rust
   ensure!(core::str::from_utf8(bytes).is_ok(), Error::<T>::InvalidUtf8);
   ```
+
 - **MUST ALWAYS** check bounds before operations:
+
   ```rust
   ensure!(value <= T::MaxValue::get(), Error::<T>::ValueTooLarge);
   ```
@@ -169,10 +188,10 @@ cargo build --release                # Build the node
 - **MUST NEVER** use repetitive and redundant comments within code
 - **MUST NEVER** ignore compiler or clippy warnings with `#[allow(...)]`
 
-### Before committing:
+### Before committing
 
 1. **MUST** run `cargo fmt`
 2. **MUST** run `just check` and fix all warnings
 3. **MUST** run `just test` and ensure all pass
 4. **MUST** run `cargo xtask coverage` to verify coverage
-5. **MUST** test runtime upgrades if storage changed
+5. **MUST** test runtime upgrades if storage changed

CONTRIBUTING.md

@@ -67,6 +67,11 @@ Be idiomatic. Use `Iterator`s, `Result`s, etc. PLEASE. Take a look at [Rust's AP
   - the WASM runtime that Substrate runs on cannot unwind, so panics in functions like `on_initialize` will halt the chain (been there - more than once);
   - use `Option` and `Result` types properly for error handling. NEVER allow `unused_must_use`. NEVER;
   - always prefer panic-free functions and treat all potential errors (`checked_div` in favor of `/`, etc.).
+- **Avoid Rust keywords as field names:**
+  - Never use Rust keywords (`type`, `use`, `trait`, `impl`, etc.) as struct field names, especially in public APIs;
+  - keywords require the `r#` prefix in Rust (e.g., `r#type`), which causes serialization inconsistencies across language bindings;
+  - Polkadot.js may convert `r#type` to `r_type` or `rType`, while Serde serializes it as `type`, creating confusion;
+  - use alternative names like `kind`, `variant`, `scope`, `category`, or `mode` instead.
 
 ## Storage modifications and migrations