refactor(agent-loop): unify tool-call scheduling on one rolling pool + factory cap default

Run every ordered group through the same rolling pool: an exclusive call is a
pool of one (a barrier), dropping the separate runExclusive path and the
redundant post-grouping executionMode re-query. Behavior is unchanged — the
parallel-tool-calls snapshot and the full scheduler unit suite (barriers, cap,
abort, model-order results) stay green.

Add AgentLoop.Config.maxParallelToolCalls as a factory-wide default applied to
every agent create/createAgent/resume mints (per-agent option overrides it),
forwarded through agent-core so it reaches front doors that expose no cap field
of their own. Trim the isConcurrencySafe JSDoc to the local contract and link
the parallel-tool-call RFC for the full rationale; document the field on the
canonical core-data-structures page.

packages/core/agent-core/README.md

@@ -39,11 +39,11 @@ This is the [interface/implementation/consumer seam](../../../docs/rfc/implement
 
 ```ts
 import type { Config } from '@deepseek-ai/dsh-agent-core'
-// { agents?, persona?, toolOrder?, tools?, skills? } — the schema intersects the owner schemas,
-// so validation and defaulting can never drift from the owners.
+// { agents?, maxParallelToolCalls?, persona?, toolOrder?, tools?, skills? } — the schema
+// intersects the owner schemas, so validation and defaulting can never drift from the owners.
 ```
 
-The bundle FORWARDS each field to the child that owns it: `agents` to `agent-loop` (default `[]`), so each app supplies its own pre-created agents — a stdio app pre-creates a `main`; the ACP app pre-creates none (it creates agents on demand at `session/new`) — `persona` and `toolOrder` to `dsh-system-prompt`; `tools` to the tool registry for its presentation mode; and `skills.registry`, `skills.local`, and `skills.tool` to the skill registry, local provider, and model-facing consumer. Forwarding is exactly why the owners can live in the shared spine even though the apps disagree on what to configure.
+The bundle FORWARDS each field to the child that owns it: `agents` to `agent-loop` (default `[]`), so each app supplies its own pre-created agents — a stdio app pre-creates a `main`; the ACP app pre-creates none (it creates agents on demand at `session/new`) — `maxParallelToolCalls` to `agent-loop` as the factory-wide default concurrent tool-call cap for every agent it creates; `persona` and `toolOrder` to `dsh-system-prompt`; `tools` to the tool registry for its presentation mode; and `skills.registry`, `skills.local`, and `skills.tool` to the skill registry, local provider, and model-facing consumer. Forwarding is exactly why the owners can live in the shared spine even though the apps disagree on what to configure.
 
 ## Why a code bundle, not a shared YAML include
 

packages/core/agent-core/src/index.ts

@@ -46,6 +46,11 @@ export interface SkillConfig {
 export interface Config {
   /** The agent-loop `agents` list (see dsh-agent-loop's `Config`). */
   agents?: AgentLoopConfig['agents']
+  /**
+   * The factory-wide default concurrent tool-call cap applied to every agent
+   * this bundle creates (see dsh-agent-loop's `Config.maxParallelToolCalls`).
+   */
+  maxParallelToolCalls?: AgentLoopConfig['maxParallelToolCalls']
   /** The deployment persona (see dsh-system-prompt's `Config`). */
   persona?: SystemPromptConfig['persona']
   /** The explicit model-facing tool order (see dsh-system-prompt's `Config`). */
@@ -95,5 +100,8 @@ export function apply(ctx: Context, config: Config): void {
   ctx.plugin(invariants)
   ctx.plugin(toolBash)
   ctx.plugin(toolSkill, config.skills?.tool ?? {})
-  ctx.plugin(AgentLoop, { agents: config.agents ?? [] })
+  ctx.plugin(AgentLoop, {
+    agents: config.agents ?? [],
+    ...config.maxParallelToolCalls !== undefined ? { maxParallelToolCalls: config.maxParallelToolCalls } : {},
+  })
 }

packages/core/agent-core/tests/agent-core.spec.ts

@@ -117,6 +117,16 @@ describe('dsh-agent-core bundle', () => {
     await ctx.fiber.dispose()
   })
 
+  it('forwards the factory-wide maxParallelToolCalls default to agents without a per-agent cap', async () => {
+    const ctx = await mount({
+      agents: [{ id: AgentId('main'), model: 'mock' }],
+      maxParallelToolCalls: 3,
+    })
+    const main = ctx.get('agents')?.get(AgentId('main'))
+    expect(main?.options.maxParallelToolCalls).toBe(3)
+    await ctx.fiber.dispose()
+  })
+
   it('tolerates a schema-bypassing direct apply (the ?? fallbacks fire)', async () => {
     // ctx.plugin validates + defaults the bundle config first; a direct apply
     // skips the schema, so the forwarding `?? []` / `?? ''` are what fire.