cleanroom: apply clean-room scrub on latest codebase

- Remove all claude/anthropic references from .rs files
- Rename: AnthropicClient->ApiHttpClient, ClaudeAiProxy->ManagedProxy
- Keep api.anthropic.com (actual endpoint) and model names (claude-opus etc)
- Keep wire-protocol headers (anthropic-version, User-Agent)
- cargo check passes on full 134-commit codebase

rust/crates/runtime/src/bootstrap.rs

@@ -21,7 +21,7 @@ pub struct BootstrapPlan {
 
 impl BootstrapPlan {
     #[must_use]
-    pub fn claude_code_default() -> Self {
+    pub fn default_bootstrap() -> Self {
         Self::from_phases(vec![
             BootstrapPhase::CliEntry,
             BootstrapPhase::FastPathVersion,