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/tui/tests/suite/vt100_history.rs

@@ -23,20 +23,20 @@ macro_rules! assert_contains {
 }
 
 struct TestScenario {
-    term: codex_tui::custom_terminal::Terminal<VT100Backend>,
+    term: llmx_tui::custom_terminal::Terminal<VT100Backend>,
 }
 
 impl TestScenario {
     fn new(width: u16, height: u16, viewport: Rect) -> Self {
         let backend = VT100Backend::new(width, height);
-        let mut term = codex_tui::custom_terminal::Terminal::with_options(backend)
+        let mut term = llmx_tui::custom_terminal::Terminal::with_options(backend)
             .expect("failed to construct terminal");
         term.set_viewport_area(viewport);
         Self { term }
     }
 
     fn run_insert(&mut self, lines: Vec<Line<'static>>) {
-        codex_tui::insert_history::insert_history_lines(&mut self.term, lines)
+        llmx_tui::insert_history::insert_history_lines(&mut self.term, lines)
             .expect("Failed to insert history lines in test");
     }
 }