## What
Adds a **Global Max Concurrent** slider to two operator surfaces and
groups the Scheduling settings by scope.
- **Footer engine menu** (`EngineControlMenu`) and **Command Center →
Concurrency card** (`CommandCenterControls`) each get a global-cap
slider.
- **Settings → Scheduling** (`SchedulingSection`) now groups fields
under labeled **"Global — applies to all projects"** and **"This
project"** subheadings with scope badges (clearer on mobile, and
surfaces the existing `globalMaxConcurrent` field that was easy to
miss).
## How
Both sliders are backed by a single shared `useGlobalConcurrency` hook
(module-level store + subscribers), so they read/write **one source of
truth** and **revalidate after every `PUT /api/global-concurrency`**.
This avoids the last-writer-wins / stale-clobber races that two
independent per-component caches would cause (which would ironically
re-create a "global cap resets" symptom). The hook also:
- treats a fetch error as **non-interactive** (slider disabled, not
stuck showing `1` and persistable),
- surfaces a **save-state** indicator (Saving…/Saved/Save failed)
mirroring the project sliders,
- **flushes a pending edit on menu close / unmount** so a quick
drag-then-dismiss isn't silently dropped.
## Review
These race/feedback behaviors were hardened in response to a multi-agent
`/code-review` (correctness, adversarial, reliability, frontend-races
all flagged the per-component-cache approach). Independent of the
companion fix PR (global-settings reset).
## Verification
- `pnpm --filter @fusion/dashboard run typecheck` — clean
- eslint on changed files — clean
- Not yet browser-verified (next step).
🤖 Generated with [Claude Code](https://claude.com/claude-code)
<!-- stage-review-badge-begin -->
---
<a href="https://stagereview.app/Runfusion/Fusion/pull/1786">
<picture>
<source media="(prefers-color-scheme: dark)"
srcset="https://stagereview.app/assets/gh-open-in-stage-dark.svg">
<img src="https://stagereview.app/assets/gh-open-in-stage-light.svg"
alt="Open in Stage">
</picture>
</a>
<!-- stage-review-badge-end -->
<!-- This is an auto-generated comment: release notes by coderabbit.ai
-->
## Summary by CodeRabbit
* **New Features**
* Added a global concurrency slider that applies across all projects.
* Global and per-project scheduling controls are now clearly separated
with scope labels and badges.
* The concurrency setting now stays in sync across different dashboard
views and saves automatically after brief pauses.
* **Bug Fixes**
* Improved feedback for loading, saving, and error states.
* Prevented confusion between global settings and project-specific
settings, especially on smaller screens.
<!-- end of auto-generated comment: release notes by coderabbit.ai -->
e335acc235
