feat: implement Multilevel Queue (MLQ) scheduling algorithm

- Added MLQ scheduling logic in multilevel.ts, including queue selection, preemption rules, and quantum expiration checks.
- Updated SchedulerConfig to include mlqQueues for MLQ configuration.
- Created default MLQ queue definitions for use in presets and process store.
- Modified process store to auto-increment process IDs.
- Enhanced tests for MLQ scheduling, covering selection, preemption, quantum expiration, and integration scenarios.
- Updated existing presets to support MLQ and adjusted process definitions to include auto-incremented IDs.

src/store/processStore.ts

@@ -1,11 +1,17 @@
 import { create } from "zustand";
 import { persist } from "zustand/middleware";
-import type { Process, SchedulerConfig } from "@core/types";
+import type { MlqQueueDef, Process, SchedulerConfig } from "@core/types";
 
 // ============================================================
 // Defaults
 // ============================================================
 
+const DEFAULT_MLQ_QUEUES: MlqQueueDef[] = [
+  { priorityMin: 1, priorityMax: 3, algorithm: "RR", quantum: 2 },
+  { priorityMin: 4, priorityMax: 7, algorithm: "PRIORITY_NP", quantum: 2 },
+  { priorityMin: 8, priorityMax: 10, algorithm: "FCFS", quantum: 2 },
+];
+
 const DEFAULT_CONFIG: SchedulerConfig = {
   algorithm: "FCFS",
   quantum: 2,
@@ -13,6 +19,7 @@ const DEFAULT_CONFIG: SchedulerConfig = {
   isPreemptive: false,
   agingEnabled: false,
   agingInterval: 5,
+  mlqQueues: DEFAULT_MLQ_QUEUES,
 };
 
 // ============================================================
@@ -22,6 +29,7 @@ const DEFAULT_CONFIG: SchedulerConfig = {
 interface ProcessStore {
   processes: Process[];
   config: SchedulerConfig;
+  _nextPid: number;
 
   addProcess: (p: Process) => void;
   updateProcess: (id: string, updates: Partial<Process>) => void;
@@ -36,9 +44,13 @@ export const useProcessStore = create<ProcessStore>()(
     (set) => ({
       processes: [],
       config: DEFAULT_CONFIG,
+      _nextPid: 1,
 
       addProcess: (p) =>
-        set((s) => ({ processes: [...s.processes, p] })),
+        set((s) => ({
+          processes: [...s.processes, { ...p, pid: s._nextPid }],
+          _nextPid: s._nextPid + 1,
+        })),
 
       updateProcess: (id, updates) =>
         set((s) => ({
@@ -50,12 +62,17 @@ export const useProcessStore = create<ProcessStore>()(
       removeProcess: (id) =>
         set((s) => ({ processes: s.processes.filter((p) => p.id !== id) })),
 
-      clearProcesses: () => set({ processes: [] }),
+      clearProcesses: () => set({ processes: [], _nextPid: 1 }),
 
       setConfig: (updates) =>
         set((s) => ({ config: { ...s.config, ...updates } })),
 
-      loadPreset: (processes, config) => set({ processes, config }),
+      loadPreset: (processes, config) =>
+        set({
+          processes,
+          config,
+          _nextPid: processes.reduce((max, p) => Math.max(max, p.pid ?? 0), 0) + 1,
+        }),
     }),
     { name: "pss:session" },
   ),