perf(agent): stabilkan async & parallel — satu runtime, bounded concurrency, isolasi error

Seperti Claude Code: satu runtime shared, concurrency dibatasi, error
subagent terisolasi (satu node gagal tidak menggagalkan cycle).

- feat(runtime): global tokio runtime via OnceLock — ganti 9+ titik
  Runtime::new() per tool call (spawn, parallel_delegate, workflow,
  explore, dir_cache, daemon handler). Hemat resource, hilangkan panic
  path Runtime::new().expect() di daemon compaction.
- fix(workflow): execute_cycle ganti try_join_all (fail-fast) →
  buffer_unordered(8) + isolasi error per node; node gagal di-log dan
  diganti [ERROR], hasil node lain tetap dipakai (Claude Code-style).
- fix(parallel_delegate): spawn subagent dibatasi per batch max_parallel
  (tidak unbounded threads).
- perf(subagent): run_agent adaptif max_tokens (800/1600/4096), temp 0.2,
  truncate tool output 12k, error-recovery note utk tool error berulang.
- test: runtime singleton + block_on (2 test).

Cargo.lock

@@ -4862,7 +4862,7 @@ dependencies = [
 
 [[package]]
 name = "zesdex-api"
-version = "1.18.4"
+version = "1.19.0"
 dependencies = [
  "anyhow",
  "argon2",
@@ -4885,7 +4885,7 @@ dependencies = [
 
 [[package]]
 name = "zesdex-application"
-version = "1.18.4"
+version = "1.19.0"
 dependencies = [
  "anyhow",
  "base64",
@@ -4902,7 +4902,7 @@ dependencies = [
 
 [[package]]
 name = "zesdex-bootstrap"
-version = "1.18.4"
+version = "1.19.0"
 dependencies = [
  "anyhow",
  "chrono",
@@ -4919,7 +4919,7 @@ dependencies = [
 
 [[package]]
 name = "zesdex-daemon"
-version = "1.18.4"
+version = "1.19.0"
 dependencies = [
  "anyhow",
  "base64",
@@ -4943,7 +4943,7 @@ dependencies = [
 
 [[package]]
 name = "zesdex-domain"
-version = "1.18.4"
+version = "1.19.0"
 dependencies = [
  "anyhow",
  "base64",
@@ -4959,7 +4959,7 @@ dependencies = [
 
 [[package]]
 name = "zesdex-gateway"
-version = "1.18.4"
+version = "1.19.0"
 dependencies = [
  "anyhow",
  "axum",
@@ -4986,7 +4986,7 @@ dependencies = [
 
 [[package]]
 name = "zesdex-grpc"
-version = "1.18.4"
+version = "1.19.0"
 dependencies = [
  "anyhow",
  "axum",
@@ -5003,7 +5003,7 @@ dependencies = [
 
 [[package]]
 name = "zesdex-infrastructure"
-version = "1.18.4"
+version = "1.19.0"
 dependencies = [
  "anyhow",
  "argon2",
@@ -5051,7 +5051,7 @@ dependencies = [
 
 [[package]]
 name = "zesdex-tui"
-version = "1.18.4"
+version = "1.19.0"
 dependencies = [
  "anyhow",
  "base64",
@@ -5077,7 +5077,7 @@ dependencies = [
 
 [[package]]
 name = "zesdex-web"
-version = "1.18.4"
+version = "1.19.0"
 dependencies = [
  "anyhow",
  "axum",
@@ -5097,7 +5097,7 @@ dependencies = [
 
 [[package]]
 name = "zesdex-ws"
-version = "1.18.4"
+version = "1.19.0"
 dependencies = [
  "anyhow",
  "axum",