feat: API timeout config, Retry-After header support, and configurable retry

- Add TimeoutConfig to HTTP client builder with connect_timeout (30s)
  and request_timeout (5min) defaults, configurable via
  CLAW_API_CONNECT_TIMEOUT and CLAW_API_REQUEST_TIMEOUT env vars
- Add with_timeout() builder to both AnthropicClient and
  OpenAiCompatClient for per-client timeout configuration
- Parse Retry-After header on 429 responses and use it to override
  exponential backoff delay when present
- Add ApiTimeoutConfig to runtime config with apiTimeout settings
  in ~/.claw/settings.json (connectTimeout, requestTimeout, maxRetries)
- Add retry_after field to ApiError::Api for propagating rate limit
  backoff hints through the retry pipeline

rust/crates/runtime/src/config.rs

@@ -81,6 +81,27 @@ pub struct RuntimePluginConfig {
     max_output_tokens: Option<u32>,
 }
 
+/// API timeout and retry configuration.
+#[derive(Debug, Clone, PartialEq, Eq)]
+pub struct ApiTimeoutConfig {
+    /// Connect timeout in seconds. Defaults to 30.
+    pub connect_timeout_secs: u64,
+    /// Request timeout in seconds. Defaults to 300 (5 minutes).
+    pub request_timeout_secs: u64,
+    /// Maximum retry attempts on transient failures. Defaults to 8.
+    pub max_retries: u32,
+}
+
+impl Default for ApiTimeoutConfig {
+    fn default() -> Self {
+        Self {
+            connect_timeout_secs: 30,
+            request_timeout_secs: 300,
+            max_retries: 8,
+        }
+    }
+}
+
 /// Structured feature configuration consumed by runtime subsystems.
 #[derive(Debug, Clone, PartialEq, Eq, Default)]
 pub struct RuntimeFeatureConfig {
@@ -95,6 +116,7 @@ pub struct RuntimeFeatureConfig {
     sandbox: SandboxConfig,
     provider_fallbacks: ProviderFallbackConfig,
     trusted_roots: Vec<String>,
+    api_timeout: ApiTimeoutConfig,
 }
 
 /// Ordered chain of fallback model identifiers used when the primary
@@ -353,6 +375,7 @@ impl ConfigLoader {
             sandbox: parse_optional_sandbox_config(&merged_value)?,
             provider_fallbacks: parse_optional_provider_fallbacks(&merged_value)?,
             trusted_roots: parse_optional_trusted_roots(&merged_value)?,
+            api_timeout: parse_optional_api_timeout_config(&merged_value)?,
         };
 
         Ok(RuntimeConfig {
@@ -410,6 +433,7 @@ impl ConfigLoader {
             sandbox: parse_optional_sandbox_config(&merged_value)?,
             provider_fallbacks: parse_optional_provider_fallbacks(&merged_value)?,
             trusted_roots: parse_optional_trusted_roots(&merged_value)?,
+            api_timeout: parse_optional_api_timeout_config(&merged_value)?,
         };
 
         let config = RuntimeConfig {
@@ -1152,6 +1176,28 @@ fn parse_optional_provider_fallbacks(
     Ok(ProviderFallbackConfig { primary, fallbacks })
 }
 
+fn parse_optional_api_timeout_config(root: &JsonValue) -> Result<ApiTimeoutConfig, ConfigError> {
+    let Some(timeout_value) = root.as_object().and_then(|obj| obj.get("apiTimeout")) else {
+        return Ok(ApiTimeoutConfig::default());
+    };
+    let Some(obj) = timeout_value.as_object() else {
+        return Ok(ApiTimeoutConfig::default());
+    };
+    let context = "merged settings.apiTimeout";
+    let connect_timeout_secs = optional_u64(obj, "connectTimeout", context)?
+        .unwrap_or(30);
+    let request_timeout_secs = optional_u64(obj, "requestTimeout", context)?
+        .unwrap_or(300);
+    let max_retries = optional_u64(obj, "maxRetries", context)?
+        .map(|v| v as u32)
+        .unwrap_or(8);
+    Ok(ApiTimeoutConfig {
+        connect_timeout_secs,
+        request_timeout_secs,
+        max_retries,
+    })
+}
+
 fn parse_optional_trusted_roots(root: &JsonValue) -> Result<Vec<String>, ConfigError> {
     let Some(object) = root.as_object() else {
         return Ok(Vec::new());

rust/crates/runtime/src/lib.rs

@@ -65,12 +65,13 @@ pub use compact::{
     get_compact_continuation_message, should_compact, CompactionConfig, CompactionResult,
 };
 pub use config::{
-    suppress_config_warnings_for_json_mode, ConfigEntry, ConfigError, ConfigLoader, ConfigSource,
+    ApiTimeoutConfig, ConfigEntry, ConfigError, ConfigLoader, ConfigSource,
     McpConfigCollection, McpManagedProxyServerConfig, McpOAuthConfig, McpRemoteServerConfig,
     McpSdkServerConfig, McpServerConfig, McpStdioServerConfig, McpTransport,
     McpWebSocketServerConfig, OAuthConfig, ProviderFallbackConfig, ResolvedPermissionMode,
     RuntimeConfig, RuntimeFeatureConfig, RuntimeHookConfig, RuntimePermissionRuleConfig,
-    RuntimePluginConfig, ScopedMcpServerConfig, CLAW_SETTINGS_SCHEMA_NAME,
+    RuntimePluginConfig, ScopedMcpServerConfig, suppress_config_warnings_for_json_mode,
+    CLAW_SETTINGS_SCHEMA_NAME,
 };
 pub use config_validate::{
     check_unsupported_format, format_diagnostics, validate_config_file, ConfigDiagnostic,