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/tui/src/shimmer.rs

@@ -0,0 +1,80 @@
+use std::sync::OnceLock;
+use std::time::Duration;
+use std::time::Instant;
+
+use ratatui::style::Color;
+use ratatui::style::Modifier;
+use ratatui::style::Style;
+use ratatui::text::Span;
+
+use crate::color::blend;
+use crate::terminal_palette::default_bg;
+use crate::terminal_palette::default_fg;
+
+static PROCESS_START: OnceLock<Instant> = OnceLock::new();
+
+fn elapsed_since_start() -> Duration {
+    let start = PROCESS_START.get_or_init(Instant::now);
+    start.elapsed()
+}
+
+pub(crate) fn shimmer_spans(text: &str) -> Vec<Span<'static>> {
+    let chars: Vec<char> = text.chars().collect();
+    if chars.is_empty() {
+        return Vec::new();
+    }
+    // Use time-based sweep synchronized to process start.
+    let padding = 10usize;
+    let period = chars.len() + padding * 2;
+    let sweep_seconds = 2.0f32;
+    let pos_f =
+        (elapsed_since_start().as_secs_f32() % sweep_seconds) / sweep_seconds * (period as f32);
+    let pos = pos_f as usize;
+    let has_true_color = supports_color::on_cached(supports_color::Stream::Stdout)
+        .map(|level| level.has_16m)
+        .unwrap_or(false);
+    let band_half_width = 5.0;
+
+    let mut spans: Vec<Span<'static>> = Vec::with_capacity(chars.len());
+    let base_color = default_fg().unwrap_or((128, 128, 128));
+    let highlight_color = default_bg().unwrap_or((255, 255, 255));
+    for (i, ch) in chars.iter().enumerate() {
+        let i_pos = i as isize + padding as isize;
+        let pos = pos as isize;
+        let dist = (i_pos - pos).abs() as f32;
+
+        let t = if dist <= band_half_width {
+            let x = std::f32::consts::PI * (dist / band_half_width);
+            0.5 * (1.0 + x.cos())
+        } else {
+            0.0
+        };
+        let style = if has_true_color {
+            let highlight = t.clamp(0.0, 1.0);
+            let (r, g, b) = blend(highlight_color, base_color, highlight * 0.9);
+            // Allow custom RGB colors, as the implementation is thoughtfully
+            // adjusting the level of the default foreground color.
+            #[allow(clippy::disallowed_methods)]
+            {
+                Style::default()
+                    .fg(Color::Rgb(r, g, b))
+                    .add_modifier(Modifier::BOLD)
+            }
+        } else {
+            color_for_level(t)
+        };
+        spans.push(Span::styled(ch.to_string(), style));
+    }
+    spans
+}
+
+fn color_for_level(intensity: f32) -> Style {
+    // Tune fallback styling so the shimmer band reads even without RGB support.
+    if intensity < 0.2 {
+        Style::default().add_modifier(Modifier::DIM)
+    } else if intensity < 0.6 {
+        Style::default()
+    } else {
+        Style::default().add_modifier(Modifier::BOLD)
+    }
+}