feat(irc): add interactive setup

feat(gateway): refine Platform._missing_ and platform-connected dispatch

Restricts plugin-name acceptance to bundled plugin scan + registry
(no arbitrary string -> enum-pollution), pulls per-platform connectivity
checks into a _PLATFORM_CONNECTED_CHECKERS lambda map with a clean
_is_platform_connected method, and adds tests covering the checker map,
plugin platform interface, and IRC setup wizard.

ui-tui/src/lib/memoryMonitor.ts

@@ -1,3 +1,5 @@
+import { evictInkCaches } from '@hermes/ink'
+
 import { type HeapDumpResult, performHeapDump } from './memory.js'
 
 export type MemoryLevel = 'critical' | 'high' | 'normal'
@@ -71,6 +73,10 @@ export function startMemoryMonitor({
       return
     }
 
+    // Prune Ink content caches before dump/exit — half on 'high' (recoverable),
+    // full on 'critical' (post-dump RSS reduction, keeps user running).
+    evictInkCaches(level === 'critical' ? 'all' : 'half')
+
     if (dumped.has(level) || inFlight.has(level)) {
       return
     }