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/undo.rs

@@ -8,13 +8,13 @@ use std::sync::Arc;
 use anyhow::Context;
 use anyhow::Result;
 use anyhow::bail;
-use codex_core::CodexConversation;
-use codex_core::config::Config;
-use codex_core::features::Feature;
-use codex_core::model_family::find_family_for_model;
-use codex_core::protocol::EventMsg;
-use codex_core::protocol::Op;
-use codex_core::protocol::UndoCompletedEvent;
+use llmx_core::CodexConversation;
+use llmx_core::config::Config;
+use llmx_core::features::Feature;
+use llmx_core::model_family::find_family_for_model;
+use llmx_core::protocol::EventMsg;
+use llmx_core::protocol::Op;
+use llmx_core::protocol::UndoCompletedEvent;
 use core_test_support::responses::ev_apply_patch_function_call;
 use core_test_support::responses::ev_assistant_message;
 use core_test_support::responses::ev_completed;