refactor(memory): replace MemoryManagerAgent with prompt-driven memory editing across four tiers (#25716)

packages/cli/src/config/config.ts

@@ -617,7 +617,7 @@ export async function loadCliConfig(
     .getExtensions()
     .find((ext) => ext.isActive && ext.plan?.directory)?.plan;
 
-  const experimentalJitContext = settings.experimental.jitContext;
+  const experimentalJitContext = settings.experimental.jitContext ?? true;
 
   let extensionRegistryURI =
     process.env['GEMINI_CLI_EXTENSION_REGISTRY_URI'] ??
@@ -991,8 +991,8 @@ export async function loadCliConfig(
     enableEventDrivenScheduler: true,
     skillsSupport: settings.skills?.enabled ?? true,
     disabledSkills: settings.skills?.disabled,
-    experimentalJitContext: settings.experimental?.jitContext,
-    experimentalMemoryManager: settings.experimental?.memoryManager,
+    experimentalJitContext,
+    experimentalMemoryV2: settings.experimental?.memoryV2,
     experimentalAutoMemory: settings.experimental?.autoMemory,
     contextManagement,
     modelSteering: settings.experimental?.modelSteering,

packages/cli/src/config/settingsSchema.ts

@@ -2140,8 +2140,9 @@ const SETTINGS_SCHEMA = {
         label: 'JIT Context Loading',
         category: 'Experimental',
         requiresRestart: true,
-        default: false,
-        description: 'Enable Just-In-Time (JIT) context loading.',
+        default: true,
+        description:
+          'Enable Just-In-Time (JIT) context loading. Defaults to true; set to false to opt out and load all GEMINI.md files into the system instruction up-front.',
         showInDialog: false,
       },
       useOSC52Paste: {
@@ -2274,14 +2275,14 @@ const SETTINGS_SCHEMA = {
           },
         },
       },
-      memoryManager: {
+      memoryV2: {
         type: 'boolean',
-        label: 'Memory Manager Agent',
+        label: 'Memory v2',
         category: 'Experimental',
         requiresRestart: true,
         default: false,
         description:
-          'Replace the built-in save_memory tool with a memory manager subagent that supports adding, removing, de-duplicating, and organizing memories.',
+          'Disable the built-in save_memory tool and let the main agent persist project context by editing markdown files directly with edit/write_file. Routes facts across four tiers: team-shared conventions go to project GEMINI.md files, project-specific personal notes go to the per-project private memory folder (MEMORY.md as index + sibling .md files for detail), and cross-project personal preferences go to the global ~/.gemini/GEMINI.md (the only file under ~/.gemini/ that the agent can edit — settings, credentials, etc. remain off-limits).',
         showInDialog: true,
       },
       autoMemory: {

packages/cli/src/test-utils/mockConfig.ts

@@ -38,7 +38,7 @@ export const createMockConfig = (overrides: Partial<Config> = {}): Config =>
       fireSessionEndEvent: vi.fn().mockResolvedValue(undefined),
       fireSessionStartEvent: vi.fn().mockResolvedValue(undefined),
     })),
-    isMemoryManagerEnabled: vi.fn(() => false),
+    isMemoryV2Enabled: vi.fn(() => false),
     isAutoMemoryEnabled: vi.fn(() => false),
     getListExtensions: vi.fn(() => false),
     getExtensions: vi.fn(() => []),