Phase 2: Rust Workspace Transformation (Part 1)

- Renamed directory: codex-backend-openapi-models -> llmx-backend-openapi-models
- Updated all Cargo.toml files:
  - Package names: codex-* -> llmx-*
  - Library names: codex_* -> llmx_*
  - Workspace dependencies updated
- Renamed Rust source files:
  - codex*.rs -> llmx*.rs (all modules)
  - codex_conversation -> llmx_conversation
  - codex_delegate -> llmx_delegate
  - codex_message_processor -> llmx_message_processor
  - codex_tool_* -> llmx_tool_*
- Updated all Rust imports:
  - use codex_* -> use llmx_*
  - mod codex* -> mod llmx*
- Updated environment variables in code:
  - CODEX_HOME -> LLMX_HOME
  - .codex -> .llmx paths
- Updated protocol crate lib name for proper linking

Note: Some compilation errors remain (type inference issues) but all
renaming is complete. Will fix compilation in next phase.

🤖 Generated with Claude Code

llmx-rs/core/tests/suite/exec.rs

@@ -3,17 +3,17 @@
 use std::collections::HashMap;
 use std::string::ToString;
 
-use codex_core::exec::ExecParams;
-use codex_core::exec::ExecToolCallOutput;
-use codex_core::exec::SandboxType;
-use codex_core::exec::process_exec_tool_call;
-use codex_core::protocol::SandboxPolicy;
-use codex_core::spawn::CODEX_SANDBOX_ENV_VAR;
+use llmx_core::exec::ExecParams;
+use llmx_core::exec::ExecToolCallOutput;
+use llmx_core::exec::SandboxType;
+use llmx_core::exec::process_exec_tool_call;
+use llmx_core::protocol::SandboxPolicy;
+use llmx_core::spawn::CODEX_SANDBOX_ENV_VAR;
 use tempfile::TempDir;
 
-use codex_core::error::Result;
+use llmx_core::error::Result;
 
-use codex_core::get_platform_sandbox;
+use llmx_core::get_platform_sandbox;
 
 fn skip_test() -> bool {
     if std::env::var(CODEX_SANDBOX_ENV_VAR) == Ok("seatbelt".to_string()) {