feat: add timestamps to process logs and inspector UI

Backend changes:
- Add timestamps to log lines: [2026-01-30T12:32:45.123Z] <line>
- stdout.log and stderr.log get timestamps per line
- combined.log includes [stdout]/[stderr] prefix after timestamp
- Add strip_timestamps query param to GET /process/{id}/logs
- Use time crate with RFC3339 format for timestamps

Frontend changes:
- Add Processes tab to inspector debug panel
- Show list of processes with status badges (running/stopped/killed)
- Click to expand and view logs
- Log viewer options:
  - Select stream: combined, stdout, stderr
  - Toggle strip_timestamps
  - Refresh logs button
- Action buttons: stop (SIGTERM), kill (SIGKILL), delete
- Auto-refresh process list every 5 seconds

frontend/packages/inspector/src/components/debug/DebugPanel.tsx

@@ -1,11 +1,12 @@
-import { Cloud, PlayCircle, Terminal } from "lucide-react";
+import { Cloud, PlayCircle, Terminal, Cpu } from "lucide-react";
 import type { AgentInfo, AgentModeInfo, UniversalEvent } from "sandbox-agent";
 import AgentsTab from "./AgentsTab";
 import EventsTab from "./EventsTab";
+import ProcessesTab from "./ProcessesTab";
 import RequestLogTab from "./RequestLogTab";
 import type { RequestLog } from "../../types/requestLog";
 
-export type DebugTab = "log" | "events" | "agents";
+export type DebugTab = "log" | "events" | "agents" | "processes";
 
 const DebugPanel = ({
   debugTab,
@@ -24,7 +25,9 @@ const DebugPanel = ({
   onRefreshAgents,
   onInstallAgent,
   agentsLoading,
-  agentsError
+  agentsError,
+  baseUrl,
+  token
 }: {
   debugTab: DebugTab;
   onDebugTabChange: (tab: DebugTab) => void;
@@ -43,6 +46,8 @@ const DebugPanel = ({
   onInstallAgent: (agentId: string, reinstall: boolean) => void;
   agentsLoading: boolean;
   agentsError: string | null;
+  baseUrl: string;
+  token?: string;
 }) => {
   return (
     <div className="debug-panel">
@@ -60,6 +65,10 @@ const DebugPanel = ({
           <Cloud className="button-icon" style={{ marginRight: 4, width: 12, height: 12 }} />
           Agents
         </button>
+        <button className={`debug-tab ${debugTab === "processes" ? "active" : ""}`} onClick={() => onDebugTabChange("processes")}>
+          <Cpu className="button-icon" style={{ marginRight: 4, width: 12, height: 12 }} />
+          Processes
+        </button>
       </div>
 
       <div className="debug-content">
@@ -92,6 +101,13 @@ const DebugPanel = ({
             error={agentsError}
           />
         )}
+
+        {debugTab === "processes" && (
+          <ProcessesTab
+            baseUrl={baseUrl}
+            token={token}
+          />
+        )}
       </div>
     </div>
   );