feat(runtime): Phase 103 CoreServices Optional化 - Memory Constraints対応

- Add CoreServicesConfig struct (from_env, minimal, all_enabled)
- Implement with_core_from_registry_optional() for selective initialization
- Update CoreBoxesImpl fields to Option<Arc<dyn XyzService>>
- Maintain backward compatibility (with_core_from_registry calls all_enabled)
- Add NYASH_CORE_DISABLE_* environment variable support
- ConsoleBox remains mandatory (Graceful Degradation principle)
- Add unit tests for optional initialization
- Update console_println! macro to handle Option type
- Fix direct console.println() calls in vm.rs and selfhost.rs
- Create core_optional_design.md documentation

Note: Phase 104 will extend ConsoleService to be optional as well with
graceful fallback in console_println! macro.

Files modified:
- src/runtime/plugin_host.rs (CoreServicesConfig, with_core_from_registry_optional, tests)
- src/runtime/core_services.rs (CoreBoxesImpl fields → Option type)
- src/runtime/mod.rs (console_println! macro updated)
- src/runner/modes/vm.rs (handle Option console)
- src/runner/selfhost.rs (handle Option console)
- docs/development/current/main/core_optional_design.md (new)
- docs/development/current/main/ring0-inventory.md (Phase 103 entry)

Test results:
- Build: ✅ Success (0 errors, 7 warnings)
- Unit tests: ✅ 3/3 passed (optional_core_tests)
- Runtime tests: ✅ 63/63 passed
- Smoke tests: ✅ 30/31 passed (1 pre-existing timeout)

src/mir/optimizer.rs

@@ -10,6 +10,7 @@
 
 use super::{MirFunction, MirInstruction, MirModule, MirType, ValueId};
 use crate::mir::optimizer_stats::OptimizationStats;
+use crate::runtime::get_global_ring0;
 
 /// MIR optimization passes
 pub struct MirOptimizer {
@@ -40,13 +41,17 @@ impl MirOptimizer {
             || std::env::var("HAKO_MIR_DISABLE_OPT").ok().as_deref() == Some("1");
         if disable_opt {
             if self.debug {
-                println!("[mir-opt] disabled by env (returning without passes)");
+                get_global_ring0()
+                    .log
+                    .debug("[mir-opt] disabled by env (returning without passes)");
             }
             return stats;
         }
 
         if self.debug {
-            println!("🚀 Starting MIR optimization passes");
+            get_global_ring0()
+                .log
+                .debug("🚀 Starting MIR optimization passes");
         }
 
         // Env toggles for phased MIR cleanup
@@ -124,7 +129,9 @@ impl MirOptimizer {
         }
 
         if self.debug {
-            println!("✅ Optimization complete: {}", stats);
+            get_global_ring0()
+                .log
+                .debug(&format!("✅ Optimization complete: {}", stats));
         }
         // Diagnostics (informational): report unlowered patterns
         let diag1 =
@@ -222,7 +229,7 @@ fn opt_debug_enabled() -> bool {
 #[allow(dead_code)]
 fn opt_debug(msg: &str) {
     if opt_debug_enabled() {
-        eprintln!("[OPT] {}", msg);
+        get_global_ring0().log.debug(&format!("[OPT] {}", msg));
     }
 }