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/RELEASE-PLAN.md

@@ -0,0 +1,121 @@
+# LLMX Release Plan
+
+## Current Status
+- Branch: `feature/rebrand-to-llmx`
+- 4 commits ready:
+  1. 831e6fa6 - Comprehensive Llmx → LLMX branding (78 files)
+  2. 424090f2 - LiteLLM setup documentation
+  3. e3507a7f - Fix default provider to litellm ⭐
+  4. a88a2f76 - Summary documentation
+- Binary: Built and tested ✅
+- LiteLLM integration: Working ✅
+
+## Recommended Strategy
+
+### Step 1: Backup Original Main Branch
+```bash
+# Create a backup tag/branch of original Llmx code
+git checkout main
+git tag original-llmx-backup
+git push origin original-llmx-backup
+
+# Or create a branch
+git branch original-llmx-main
+git push origin original-llmx-main
+```
+
+### Step 2: Merge to Main
+```bash
+git checkout main
+git merge feature/rebrand-to-llmx
+git push origin main
+```
+
+### Step 3: Create Release Tag
+```bash
+git tag -a v0.1.0 -m "Initial LLMX release with LiteLLM integration
+
+- Complete rebrand from Llmx to LLMX
+- LiteLLM provider support (Chat Completions API)
+- Default model: anthropic/claude-sonnet-4-20250514
+- Built-in support for multiple LLM providers via LiteLLM
+"
+git push origin v0.1.0
+```
+
+### Step 4: Build for NPM Release
+
+The project has npm packaging scripts in `llmx-cli/scripts/`:
+- `build_npm_package.py` - Builds the npm package
+- `install_native_deps.py` - Installs native binaries
+
+```bash
+# Build the npm package
+cd llmx-cli
+python3 scripts/build_npm_package.py
+
+# Test locally
+npm pack
+
+# Publish to npm (requires npm login)
+npm login
+npm publish --access public
+```
+
+### Step 5: Update Package Metadata
+
+Before publishing, update:
+
+1. **package.json** version:
+   ```json
+   {
+     "name": "@llmx/llmx",
+     "version": "0.1.0",
+     "description": "LLMX - AI coding assistant with LiteLLM integration"
+   }
+   ```
+
+2. **README.md** - Update installation instructions:
+   ```bash
+   npm install -g @llmx/llmx
+   ```
+
+## Alternative: Separate Repository
+
+If you want to keep original Llmx intact:
+
+1. **Fork to new repo**: `valknar/llmx` (separate from `valknar/llmx`)
+2. Push all changes there
+3. Publish from the new repo
+
+## NPM Publishing Checklist
+
+- [ ] npm account ready (@valknar or @llmx org)
+- [ ] Package name available (`@llmx/llmx` or `llmx`)
+- [ ] Version set in package.json (suggest: 0.1.0)
+- [ ] Binary built and tested
+- [ ] README updated with new name
+- [ ] LICENSE file included
+- [ ] .npmignore configured
+
+## Versioning Strategy
+
+Suggest semantic versioning:
+- **v0.1.0** - Initial LLMX release (current work)
+- **v0.2.0** - Additional features
+- **v1.0.0** - Stable release after testing
+
+## Post-Release
+
+1. Create GitHub release with changelog
+2. Update documentation
+3. Announce on relevant channels
+4. Monitor for issues
+
+## Files That Need Version Updates
+
+Before release, update version in:
+- `llmx-cli/package.json`
+- `llmx-cli/Cargo.toml`
+- `llmx-rs/cli/Cargo.toml`
+- Root `Cargo.toml` workspace