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).

apps/infrastructure/src/workflow/hive_mind/cycle.rs

@@ -1,11 +1,15 @@
 //! Hive-mind cycle execution — run one cycle of parallel nodes.
 //!
 //! Flow: load settings → resolve LLM credentials → run all directives in the
-//! cycle concurrently via try_join_all → collect Vec<NodeOutput>.
+//! cycle concurrently via a BOUNDED buffer (`buffer_unordered(MAX)`) → collect
+//! `Vec<NodeOutput>`. Unlike `try_join_all`, a single failing node does NOT
+//! fail the whole cycle — failed nodes are logged and replaced with an
+//! `[ERROR]` output so the remaining results are preserved (like Claude
+//! Code's isolated subagents).
 
 use anyhow::Result;
-use futures_util::future::try_join_all;
-use tracing::info;
+use futures_util::stream::StreamExt;
+use tracing::{info, warn};
 
 use zesdex_domain::cms::{AppConfigRepository, SettingsRepository};
 use zesdex_domain::core::Store;
@@ -15,16 +19,21 @@ use crate::subagent::context::SubagentContext;
 use crate::subagent::division::AccessTier;
 use crate::subagent::engine::run_agent;
 use crate::tools::ToolCtx;
-use zesdex_domain::workflow::{CognitiveCycle, NodeOutput};
+use zesdex_domain::workflow::{CognitiveCycle, NodeDirective, NodeOutput};
+
+/// Maximum number of hive-mind nodes running concurrently per cycle.
+/// Keeps thread/runtime pressure bounded (Claude Code-style).
+const MAX_CONCURRENT_NODES: usize = 8;
 
 /// Execute one cycle: run each node directive and collect outputs.
 ///
 /// Flow:
 ///   1. Load `Settings` and `AppConfig` from the store directory.
 ///   2. Resolve provider, model, base_url, and api_key.
-///   3. Spawn all directives concurrently — each builds a `SubagentContext`
-///      and calls `run_agent` (Full access).
-///   4. `try_join_all` waits for all to complete, then collect `NodeOutput`s.
+///   3. Spawn directives with bounded concurrency — each builds a
+///      `SubagentContext` and calls `run_agent`.
+///   4. Collect `NodeOutput`s; failed nodes are logged and replaced with an
+///      `[ERROR]` placeholder so the cycle still completes.
 pub async fn execute_cycle(cycle: &CognitiveCycle, tool_ctx: &ToolCtx) -> Result<Vec<NodeOutput>> {
     info!(
         "Executing cycle {} with {} directives",
@@ -53,10 +62,9 @@ pub async fn execute_cycle(cycle: &CognitiveCycle, tool_ctx: &ToolCtx) -> Result
 
     let cycle_index = cycle.index;
 
-    use zesdex_domain::workflow::NodeDirective;
-
-    // Run all directives in this cycle concurrently.
-    let handles: Vec<_> = cycle
+    // Run all directives with bounded concurrency. Each node is its own
+    // future; failures are collected, not propagated (isolated errors).
+    let tasks: Vec<_> = cycle
         .directives
         .iter()
         .enumerate()
@@ -79,18 +87,33 @@ pub async fn execute_cycle(cycle: &CognitiveCycle, tool_ctx: &ToolCtx) -> Result
                 _ => AccessTier::Read,
             };
 
+            let node_id = format!("Node-{}-{}", cycle_index, i);
             async move {
-                let result = run_agent(ctx, &dir, access, tc).await?;
-                Ok::<NodeOutput, anyhow::Error>(NodeOutput {
-                    id: format!("Node-{}-{}", cycle_index, i),
-                    directive: dir,
-                    output: result,
-                })
+                match run_agent(ctx, &dir, access, tc).await {
+                    Ok(output) => Ok::<NodeOutput, anyhow::Error>(NodeOutput {
+                        id: node_id.clone(),
+                        directive: dir,
+                        output,
+                    }),
+                    Err(e) => {
+                        warn!(node = %node_id, error = %e, "hive-mind node failed (isolated)");
+                        Ok::<NodeOutput, anyhow::Error>(NodeOutput {
+                            id: node_id,
+                            directive: dir,
+                            output: format!("[ERROR] {e}"),
+                        })
+                    }
+                }
             }
         })
         .collect();
 
-    let results = try_join_all(handles).await?;
+    // Bounded concurrency: run at most MAX_CONCURRENT_NODES futures at once.
+    let mut stream = futures_util::stream::iter(tasks).buffer_unordered(MAX_CONCURRENT_NODES);
+    let mut results = Vec::with_capacity(cycle.directives.len());
+    while let Some(node) = stream.next().await {
+        results.push(node?);
+    }
 
     Ok(results)
 }