feat: complete Rust port of claude-statusline

Port the entire 2236-line bash statusline script to Rust.
Implements all 25 sections, 3-phase layout engine (render, priority
drop, flex/justify), file-based caching with flock, 9-level terminal
width detection, trend sparklines, and deep-merge JSON config.

Release binary: 864K with LTO. Render time: <1ms warm.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

src/input.rs

@@ -0,0 +1,60 @@
+use serde::Deserialize;
+
+#[derive(Debug, Default, Deserialize)]
+#[serde(default)]
+pub struct InputData {
+    pub model: Option<ModelInfo>,
+    pub cost: Option<CostInfo>,
+    pub context_window: Option<ContextWindow>,
+    pub workspace: Option<Workspace>,
+    pub version: Option<String>,
+    pub output_style: Option<OutputStyle>,
+}
+
+#[derive(Debug, Default, Deserialize)]
+#[serde(default)]
+pub struct ModelInfo {
+    pub id: Option<String>,
+    pub display_name: Option<String>,
+}
+
+#[derive(Debug, Default, Deserialize)]
+#[serde(default)]
+pub struct CostInfo {
+    pub total_cost_usd: Option<f64>,
+    pub total_duration_ms: Option<u64>,
+    pub total_lines_added: Option<u64>,
+    pub total_lines_removed: Option<u64>,
+    pub total_tool_uses: Option<u64>,
+    pub last_tool_name: Option<String>,
+    pub total_turns: Option<u64>,
+}
+
+#[derive(Debug, Default, Deserialize)]
+#[serde(default)]
+pub struct ContextWindow {
+    pub used_percentage: Option<f64>,
+    pub total_input_tokens: Option<u64>,
+    pub total_output_tokens: Option<u64>,
+    pub context_window_size: Option<u64>,
+    pub current_usage: Option<CurrentUsage>,
+}
+
+#[derive(Debug, Default, Deserialize)]
+#[serde(default)]
+pub struct CurrentUsage {
+    pub cache_read_input_tokens: Option<u64>,
+    pub cache_creation_input_tokens: Option<u64>,
+}
+
+#[derive(Debug, Default, Deserialize)]
+#[serde(default)]
+pub struct Workspace {
+    pub project_dir: Option<String>,
+}
+
+#[derive(Debug, Default, Deserialize)]
+#[serde(default)]
+pub struct OutputStyle {
+    pub name: Option<String>,
+}