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/execpolicy/src/opt.rs

@@ -0,0 +1,77 @@
+#![allow(clippy::needless_lifetimes)]
+
+use crate::ArgType;
+use crate::starlark::values::ValueLike;
+use allocative::Allocative;
+use derive_more::derive::Display;
+use starlark::any::ProvidesStaticType;
+use starlark::values::AllocValue;
+use starlark::values::Heap;
+use starlark::values::NoSerialize;
+use starlark::values::StarlarkValue;
+use starlark::values::UnpackValue;
+use starlark::values::Value;
+use starlark::values::starlark_value;
+
+/// Command line option that takes a value.
+#[derive(Clone, Debug, Display, PartialEq, Eq, ProvidesStaticType, NoSerialize, Allocative)]
+#[display("opt({})", opt)]
+pub struct Opt {
+    /// The option as typed on the command line, e.g., `-h` or `--help`. If
+    /// it can be used in the `--name=value` format, then this should be
+    /// `--name` (though this is subject to change).
+    pub opt: String,
+    pub meta: OptMeta,
+    pub required: bool,
+}
+
+/// When defining an Opt, use as specific an OptMeta as possible.
+#[derive(Clone, Debug, Display, PartialEq, Eq, ProvidesStaticType, NoSerialize, Allocative)]
+#[display("{}", self)]
+pub enum OptMeta {
+    /// Option does not take a value.
+    Flag,
+
+    /// Option takes a single value matching the specified type.
+    Value(ArgType),
+}
+
+impl Opt {
+    pub fn new(opt: String, meta: OptMeta, required: bool) -> Self {
+        Self {
+            opt,
+            meta,
+            required,
+        }
+    }
+
+    pub fn name(&self) -> &str {
+        &self.opt
+    }
+}
+
+#[starlark_value(type = "Opt")]
+impl<'v> StarlarkValue<'v> for Opt {
+    type Canonical = Opt;
+}
+
+impl<'v> UnpackValue<'v> for Opt {
+    type Error = starlark::Error;
+
+    fn unpack_value_impl(value: Value<'v>) -> starlark::Result<Option<Self>> {
+        // TODO(mbolin): It fels like this should be doable without cloning?
+        // Cannot simply consume the value?
+        Ok(value.downcast_ref::<Opt>().cloned())
+    }
+}
+
+impl<'v> AllocValue<'v> for Opt {
+    fn alloc_value(self, heap: &'v Heap) -> Value<'v> {
+        heap.alloc_simple(self)
+    }
+}
+
+#[starlark_value(type = "OptMeta")]
+impl<'v> StarlarkValue<'v> for OptMeta {
+    type Canonical = OptMeta;
+}