Optimize: lazy load ai and auth-provider packages to improve initialization speed

- Make ai package import dynamic to avoid loading 2.8MB package during initialization
- Make auth-provider import dynamic to avoid loading 812KB package during initialization
- Both packages now load only when janitor runs (on session idle events)
- Combined with gpt-tokenizer lazy loading, plugin initialization is now ~58.6MB lighter
- Improves plugin startup time and reduces memory footprint

Author: Tarquinen

lib/janitor.ts

@@ -1,4 +1,3 @@
-import { generateObject } from "ai"
 import { z } from "zod"
 import type { Logger } from "./logger"
 import type { StateManager } from "./state"
@@ -328,6 +327,9 @@ export class Janitor {
                         prunedIds: allPrunedSoFar.slice(0, 5) // Show first 5
                     })
 
+                    // Lazy import - only load the 2.8MB ai package when actually needed
+                    const { generateObject } = await import('ai')
+
                     // Analyze which tool calls are obsolete
                     const result = await generateObject({
                         model: modelSelection.model,

lib/model-selector.ts

@@ -4,10 +4,12 @@
  * This module handles intelligent model selection for the DCP plugin's analysis tasks.
  * It attempts to use the same model as the current session, with fallbacks to other
  * available models when needed.
+ * 
+ * NOTE: OpencodeAI is lazily imported to avoid loading the 812KB package during
+ * plugin initialization. The package is only loaded when model selection is needed.
  */
 
 import type { LanguageModel } from 'ai';
-import { OpencodeAI } from '@tarquinen/opencode-auth-provider';
 import type { Logger } from './logger';
 
 export interface ModelInfo {
@@ -82,6 +84,9 @@ export async function selectModel(
     configModel?: string
 ): Promise<ModelSelectionResult> {
     logger?.info('model-selector', 'Model selection started', { currentModel, configModel });
+    
+    // Lazy import - only load the 812KB auth provider package when actually needed
+    const { OpencodeAI } = await import('@tarquinen/opencode-auth-provider');
     const opencodeAI = new OpencodeAI();
 
     let failedModelInfo: ModelInfo | undefined;