feat(session): persist model tier overrides per session

Store per-session config in SQLite and route /model and /reset through command fast-paths so channel sessions keep independent model selection across reconnects and restarts.

src/backends/native/orchestrator.ts

@@ -13,6 +13,7 @@ import { shouldCompact } from '../../context/tokens.js';
 import { compactHistory, type CompactionConfig, type CompactionResult, DEFAULT_COMPACTION_CONFIG } from '../../context/compaction.js';
 import { estimateCost } from '../../models/costs.js';
 import { auditLogger } from '../../audit/index.js';
+import { buildAdaptiveMemoryContext, buildRecentMemoryContext } from '../../memory/adaptive.js';
 
 // ── Public types ──────────────────────────────────────────────────────
 
@@ -91,6 +92,10 @@ export interface OrchestratorConfig {
   contextWindow?: number;
   /** Optional memory store for injecting persistent memory into the system prompt. */
   memoryStore?: MemoryStore;
+  /** Strategy for memory prompt injection. */
+  memoryInjectionStrategy?: 'all' | 'recent' | 'adaptive';
+  /** Maximum tokens allowed for injected memory context. */
+  memoryMaxInjectionTokens?: number;
   /** Policy context for tool filtering (agent tier, provider). */
   toolPolicyContext?: ToolPolicyContext;
   /** Collector for outbound attachments queued by tools (e.g. media.send). */
@@ -118,6 +123,8 @@ export class AgentOrchestrator {
   private _modelName?: string;
   private _contextWindow?: number;
   private _memoryStore?: MemoryStore;
+  private _memoryInjectionStrategy: 'all' | 'recent' | 'adaptive';
+  private _memoryMaxInjectionTokens: number;
   private _systemPromptBase: string;
   private _usageByTier: Map<string, TierUsageStats> = new Map();
 
@@ -131,6 +138,8 @@ export class AgentOrchestrator {
     this._modelName = config.modelName;
     this._contextWindow = config.contextWindow;
     this._memoryStore = config.memoryStore;
+    this._memoryInjectionStrategy = config.memoryInjectionStrategy ?? 'all';
+    this._memoryMaxInjectionTokens = config.memoryMaxInjectionTokens ?? 2000;
     this._systemPromptBase = config.systemPrompt;
 
     // Create the primary NativeAgent for user-facing conversation
@@ -216,7 +225,7 @@ export class AgentOrchestrator {
    * exceeds the context window threshold and compacts it before processing.
    */
   async process(userMessage: string, attachments?: Attachment[]): Promise<string> {
-    this._injectMemoryContext();
+    this._injectMemoryContext(userMessage);
     await this.compactIfNeeded();
     return this._agent.process(userMessage, attachments);
   }
@@ -355,12 +364,34 @@ export class AgentOrchestrator {
    * system prompt. If no memory store is configured or no memory content
    * exists, restores the original base prompt.
    */
-  private _injectMemoryContext(): void {
+  private _injectMemoryContext(userMessage: string): void {
     if (!this._memoryStore) {
       return;
     }
 
-    const memoryContext = this._memoryStore.getContextForPrompt();
+    let memoryContext = '';
+    try {
+      if (this._memoryInjectionStrategy === 'recent') {
+        memoryContext = buildRecentMemoryContext(this._memoryStore, this._memoryMaxInjectionTokens);
+      } else if (this._memoryInjectionStrategy === 'adaptive') {
+        memoryContext = buildAdaptiveMemoryContext({
+          store: this._memoryStore,
+          userMessage,
+          recentMessages: this.getHistory(),
+          config: {
+            maxTokens: this._memoryMaxInjectionTokens,
+          },
+        });
+      } else {
+        memoryContext = this._memoryStore.getContextForPrompt();
+      }
+    } catch (error) {
+      console.warn('[Flynn:memory] Adaptive memory injection failed, falling back to default context:', error);
+      memoryContext = this._memoryStore.getContextForPrompt();
+    }
+
+    memoryContext = this._clipMemoryContext(memoryContext);
+
     if (!memoryContext) {
       this._agent.setSystemPrompt(this._systemPromptBase);
       return;
@@ -370,6 +401,17 @@ export class AgentOrchestrator {
     this._agent.setSystemPrompt(enrichedPrompt);
   }
 
+  private _clipMemoryContext(context: string): string {
+    if (!context) {
+      return context;
+    }
+    const maxChars = this._memoryMaxInjectionTokens * 4;
+    if (context.length <= maxChars) {
+      return context;
+    }
+    return context.slice(0, maxChars);
+  }
+
   /**
    * Check whether automatic compaction should run, and if so, compact.
    * Called before each `process()` call when compaction is configured.