feat(coding-agent): made memory.backend the authoritative selector for memory backends

- Updated runtime memory config loading and backend resolution so `memory.backend === "local"` now enables the local pipeline directly, while `memories.enabled` is treated only as a legacy migration input.
- Switched the `memory.backend` default to `off` and kept `memories.enabled` hidden from the Memory tab UI for migration compatibility.
- Adjusted memory runtime, resolver, and documentation/tests to match the new backend-selection semantics.

packages/coding-agent/README.md

@@ -17,11 +17,9 @@ Package-specific references:
 
 The agent supports three mutually-exclusive memory backends, selected via the `memory.backend` setting (Settings → Memory tab, or `~/.omp/config.yml`):
 
-|Backend|Behaviour|
----|---|
-`off`|No memory subsystem runs.|
-`local` (default)|Existing rollout-summarisation pipeline. Writes `memory_summary.md` and consolidated artifacts under the agent dir. Additionally gated by the legacy `memories.enabled` boolean — set it to `true` to actually run.|
-`hindsight`|Talks to a [Hindsight](https://hindsight.vectorize.io) server (Cloud or self-hosted Docker). Retains transcripts every Nth user turn, recalls memories on the first turn of a session, and exposes three tools: `hindsight_retain`, `hindsight_recall`, `hindsight_reflect`.|
+- `off` (default) — no memory subsystem runs.
+- `local` — existing rollout-summarisation pipeline; writes `memory_summary.md` and consolidated artifacts under the agent dir.
+- `hindsight` — talks to a [Hindsight](https://hindsight.vectorize.io) server (Cloud or self-hosted Docker), retains transcripts every Nth user turn, recalls memories on the first turn of a session, and exposes `hindsight_retain`, `hindsight_recall`, and `hindsight_reflect`.
 
 ### Hindsight quickstart
 

packages/coding-agent/src/config/settings-schema.ts

@@ -879,14 +879,11 @@ export const SETTINGS_SCHEMA = {
 	"branchSummary.reserveTokens": { type: "number", default: 16384 },
 
 	// Memories
+	// Legacy local-memory enable flag kept only for back-compat migration.
+	// Hidden from UI — users should use `memory.backend` instead.
 	"memories.enabled": {
 		type: "boolean",
 		default: false,
-		ui: {
-			tab: "memory",
-			label: "Memories",
-			description: "Enable autonomous memory extraction and consolidation",
-		},
 	},
 
 	"memories.maxRolloutsPerStartup": { type: "number", default: 64 },
@@ -925,11 +922,11 @@ export const SETTINGS_SCHEMA = {
 	"memory.backend": {
 		type: "enum",
 		values: ["off", "local", "hindsight"] as const,
-		default: "local",
+		default: "off",
 		ui: {
 			tab: "memory",
 			label: "Memory Backend",
-			description: "Local memory pipeline, Hindsight remote memory, or off",
+			description: "Off, local memory pipeline, or Hindsight remote memory",
 			submenu: true,
 		},
 	},

packages/coding-agent/src/memories/index.ts

@@ -1077,7 +1077,7 @@ async function resolveMemoryModel(options: {
 
 function loadMemoryConfig(settings: Settings): MemoryRuntimeConfig {
 	return {
-		enabled: settings.get("memories.enabled") ?? DEFAULTS.enabled,
+		enabled: settings.get("memory.backend") === "local" || settings.get("memories.enabled") === true,
 		maxRolloutsPerStartup: settings.get("memories.maxRolloutsPerStartup") ?? DEFAULTS.maxRolloutsPerStartup,
 		maxRolloutAgeDays: settings.get("memories.maxRolloutAgeDays") ?? DEFAULTS.maxRolloutAgeDays,
 		minRolloutIdleHours: settings.get("memories.minRolloutIdleHours") ?? DEFAULTS.minRolloutIdleHours,

packages/coding-agent/src/memory-backend/off-backend.ts

@@ -3,9 +3,7 @@ import type { MemoryBackend } from "./types";
 /**
  * No-op memory backend.
  *
- * Selected when `memory.backend` is `"off"`, or when `"local"` is selected but
- * `memories.enabled` is false (preserves the historical "memories disabled by
- * default" behaviour without forcing users to flip both switches).
+ * Selected when `memory.backend` is `"off"`.
  */
 export const offBackend: MemoryBackend = {
 	id: "off",

packages/coding-agent/src/memory-backend/resolve.ts

@@ -10,16 +10,15 @@ import type { MemoryBackend } from "./types";
  * Selection rules (single source of truth — every memory consumer routes
  * through this):
  *   - `memory.backend === "hindsight"`  → Hindsight remote memory
- *   - `memory.backend === "local"` and `memories.enabled === true` → local pipeline
- *   - everything else → no-op
+ *   - `memory.backend === "local"`      → local pipeline
+ *   - everything else                   → no-op
  *
- * The legacy `memories.enabled` boolean still gates the local backend so users
- * who have it set to `false` keep getting silence, even after the new enum
- * defaults to `"local"`.
+ * `memories.enabled` remains accepted only as a legacy migration input. Once
+ * a config is loaded, `memory.backend` is the sole runtime selector.
  */
 export function resolveMemoryBackend(settings: Settings): MemoryBackend {
 	const id = settings.get("memory.backend");
 	if (id === "hindsight") return hindsightBackend;
-	if (id === "local" && settings.get("memories.enabled")) return localBackend;
+	if (id === "local") return localBackend;
 	return offBackend;
 }

packages/coding-agent/test/memories-runtime.test.ts

@@ -349,7 +349,7 @@ describe("buildMemoryToolDeveloperInstructions", () => {
 
 	test("returns undefined for missing or empty summaries", async () => {
 		const agentDir = await makeTempDir("memories-runtime-instructions");
-		const settings = Settings.isolated({ "memories.enabled": true });
+		const settings = Settings.isolated({ "memory.backend": "local" });
 
 		expect(await buildMemoryToolDeveloperInstructions(agentDir, settings)).toBeUndefined();
 
@@ -362,7 +362,7 @@ describe("buildMemoryToolDeveloperInstructions", () => {
 	test("renders payload with truncation for non-empty summary", async () => {
 		const agentDir = await makeTempDir("memories-runtime-instructions");
 		const settings = Settings.isolated({
-			"memories.enabled": true,
+			"memory.backend": "local",
 			"memories.summaryInjectionTokenLimit": 8,
 		});
 		const memoryRoot = getMemoryRoot(agentDir, settings.getCwd());

packages/coding-agent/test/memory-backend-resolve.test.ts

@@ -16,18 +16,12 @@ describe("resolveMemoryBackend", () => {
 		expect(resolveMemoryBackend(settings).id).toBe("off");
 	});
 
-	it("returns the local backend when memory.backend is local AND memories.enabled is true", () => {
-		const settings = Settings.isolated({ "memory.backend": "local", "memories.enabled": true });
+	it("returns the local backend when memory.backend is local", () => {
+		const settings = Settings.isolated({ "memory.backend": "local", "memories.enabled": false });
 		expect(resolveMemoryBackend(settings).id).toBe("local");
 	});
 
-	it("returns the off backend when memory.backend is local but memories.enabled is false", () => {
-		const settings = Settings.isolated({ "memory.backend": "local", "memories.enabled": false });
-		// Falls back to off so existing users with memories.enabled=false keep silence.
-		expect(resolveMemoryBackend(settings).id).toBe("off");
-	});
-
-	it("returns the hindsight backend when memory.backend is hindsight, regardless of memories.enabled", () => {
+	it("returns the hindsight backend when memory.backend is hindsight, regardless of legacy memories.enabled", () => {
 		const a = Settings.isolated({ "memory.backend": "hindsight", "memories.enabled": false });
 		const b = Settings.isolated({ "memory.backend": "hindsight", "memories.enabled": true });
 		expect(resolveMemoryBackend(a).id).toBe("hindsight");