feat: Complete LLMX v0.1.0 - Rebrand from Codex with LiteLLM Integration

This release represents a comprehensive transformation of the codebase from Codex to LLMX,
enhanced with LiteLLM integration to support 100+ LLM providers through a unified API.

## Major Changes

### Phase 1: Repository & Infrastructure Setup
- Established new repository structure and branching strategy
- Created comprehensive project documentation (CLAUDE.md, LITELLM-SETUP.md)
- Set up development environment and tooling configuration

### Phase 2: Rust Workspace Transformation
- Renamed all Rust crates from `codex-*` to `llmx-*` (30+ crates)
- Updated package names, binary names, and workspace members
- Renamed core modules: codex.rs → llmx.rs, codex_delegate.rs → llmx_delegate.rs
- Updated all internal references, imports, and type names
- Renamed directories: codex-rs/ → llmx-rs/, codex-backend-openapi-models/ → llmx-backend-openapi-models/
- Fixed all Rust compilation errors after mass rename

### Phase 3: LiteLLM Integration
- Integrated LiteLLM for multi-provider LLM support (Anthropic, OpenAI, Azure, Google AI, AWS Bedrock, etc.)
- Implemented OpenAI-compatible Chat Completions API support
- Added model family detection and provider-specific handling
- Updated authentication to support LiteLLM API keys
- Renamed environment variables: OPENAI_BASE_URL → LLMX_BASE_URL
- Added LLMX_API_KEY for unified authentication
- Enhanced error handling for Chat Completions API responses
- Implemented fallback mechanisms between Responses API and Chat Completions API

### Phase 4: TypeScript/Node.js Components
- Renamed npm package: @codex/codex-cli → @valknar/llmx
- Updated TypeScript SDK to use new LLMX APIs and endpoints
- Fixed all TypeScript compilation and linting errors
- Updated SDK tests to support both API backends
- Enhanced mock server to handle multiple API formats
- Updated build scripts for cross-platform packaging

### Phase 5: Configuration & Documentation
- Updated all configuration files to use LLMX naming
- Rewrote README and documentation for LLMX branding
- Updated config paths: ~/.codex/ → ~/.llmx/
- Added comprehensive LiteLLM setup guide
- Updated all user-facing strings and help text
- Created release plan and migration documentation

### Phase 6: Testing & Validation
- Fixed all Rust tests for new naming scheme
- Updated snapshot tests in TUI (36 frame files)
- Fixed authentication storage tests
- Updated Chat Completions payload and SSE tests
- Fixed SDK tests for new API endpoints
- Ensured compatibility with Claude Sonnet 4.5 model
- Fixed test environment variables (LLMX_API_KEY, LLMX_BASE_URL)

### Phase 7: Build & Release Pipeline
- Updated GitHub Actions workflows for LLMX binary names
- Fixed rust-release.yml to reference llmx-rs/ instead of codex-rs/
- Updated CI/CD pipelines for new package names
- Made Apple code signing optional in release workflow
- Enhanced npm packaging resilience for partial platform builds
- Added Windows sandbox support to workspace
- Updated dotslash configuration for new binary names

### Phase 8: Final Polish
- Renamed all assets (.github images, labels, templates)
- Updated VSCode and DevContainer configurations
- Fixed all clippy warnings and formatting issues
- Applied cargo fmt and prettier formatting across codebase
- Updated issue templates and pull request templates
- Fixed all remaining UI text references

## Technical Details

**Breaking Changes:**
- Binary name changed from `codex` to `llmx`
- Config directory changed from `~/.codex/` to `~/.llmx/`
- Environment variables renamed (CODEX_* → LLMX_*)
- npm package renamed to `@valknar/llmx`

**New Features:**
- Support for 100+ LLM providers via LiteLLM
- Unified authentication with LLMX_API_KEY
- Enhanced model provider detection and handling
- Improved error handling and fallback mechanisms

**Files Changed:**
- 578 files modified across Rust, TypeScript, and documentation
- 30+ Rust crates renamed and updated
- Complete rebrand of UI, CLI, and documentation
- All tests updated and passing

**Dependencies:**
- Updated Cargo.lock with new package names
- Updated npm dependencies in llmx-cli
- Enhanced OpenAPI models for LLMX backend

This release establishes LLMX as a standalone project with comprehensive LiteLLM
integration, maintaining full backward compatibility with existing functionality
while opening support for a wide ecosystem of LLM providers.

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

Co-Authored-By: Claude <noreply@anthropic.com>
Co-Authored-By: Sebastian Krüger <support@pivoine.art>

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

@@ -0,0 +1,78 @@
+#![cfg(not(target_os = "windows"))]
+
+use std::os::unix::fs::PermissionsExt;
+
+use core_test_support::fs_wait;
+use core_test_support::responses;
+use core_test_support::skip_if_no_network;
+use core_test_support::test_llmx::TestLlmx;
+use core_test_support::test_llmx::test_llmx;
+use core_test_support::wait_for_event;
+use llmx_core::protocol::EventMsg;
+use llmx_core::protocol::Op;
+use llmx_protocol::user_input::UserInput;
+use pretty_assertions::assert_eq;
+use serde_json::Value;
+use serde_json::json;
+use tempfile::TempDir;
+use wiremock::matchers::any;
+
+use responses::ev_assistant_message;
+use responses::ev_completed;
+use responses::sse;
+use responses::start_mock_server;
+use std::time::Duration;
+
+#[tokio::test(flavor = "multi_thread", worker_threads = 2)]
+#[ignore = "flaky on ubuntu-24.04-arm - aarch64-unknown-linux-gnu"]
+// The notify script gets far enough to create (and therefore surface) the file,
+// but hasn’t flushed the JSON yet. Reading an empty file produces EOF while parsing
+// a value at line 1 column 0. May be caused by a slow runner.
+async fn summarize_context_three_requests_and_instructions() -> anyhow::Result<()> {
+    skip_if_no_network!(Ok(()));
+
+    let server = start_mock_server().await;
+
+    let sse1 = sse(vec![ev_assistant_message("m1", "Done"), ev_completed("r1")]);
+
+    responses::mount_sse_once_match(&server, any(), sse1).await;
+
+    let notify_dir = TempDir::new()?;
+    // write a script to the notify that touches a file next to it
+    let notify_script = notify_dir.path().join("notify.sh");
+    std::fs::write(
+        &notify_script,
+        r#"#!/bin/bash
+set -e
+echo -n "${@: -1}" > $(dirname "${0}")/notify.txt"#,
+    )?;
+    std::fs::set_permissions(&notify_script, std::fs::Permissions::from_mode(0o755))?;
+
+    let notify_file = notify_dir.path().join("notify.txt");
+    let notify_script_str = notify_script.to_str().unwrap().to_string();
+
+    let TestLlmx { llmx, .. } = test_llmx()
+        .with_config(move |cfg| cfg.notify = Some(vec![notify_script_str]))
+        .build(&server)
+        .await?;
+
+    // 1) Normal user input – should hit server once.
+    llmx.submit(Op::UserInput {
+        items: vec![UserInput::Text {
+            text: "hello world".into(),
+        }],
+    })
+    .await?;
+    wait_for_event(&llmx, |ev| matches!(ev, EventMsg::TaskComplete(_))).await;
+
+    // We fork the notify script, so we need to wait for it to write to the file.
+    fs_wait::wait_for_path_exists(&notify_file, Duration::from_secs(5)).await?;
+    let notify_payload_raw = tokio::fs::read_to_string(&notify_file).await?;
+    let payload: Value = serde_json::from_str(&notify_payload_raw)?;
+
+    assert_eq!(payload["type"], json!("agent-turn-complete"));
+    assert_eq!(payload["input-messages"], json!(["hello world"]));
+    assert_eq!(payload["last-assistant-message"], json!("Done"));
+
+    Ok(())
+}