feat(memory): add explicit paths config for memory search

Add a `paths` option to `memorySearch` config, allowing users to
explicitly specify additional directories or files to include in
memory search.

Follow-up to #2961 as suggested by @gumadeiras — instead of auto-following
symlinks (which has security implications), users can now explicitly
declare additional search paths.

- Add `memorySearch.paths` config option (array of strings)
- Paths can be absolute or relative (resolved from workspace)
- Directories are recursively scanned for `.md` files
- Single `.md` files can also be specified
- Paths from defaults and agent overrides are merged
- Added 4 test cases for listMemoryFiles

src/agents/memory-search.ts

@@ -9,6 +9,7 @@ import { resolveAgentConfig } from "./agent-scope.js";
 export type ResolvedMemorySearchConfig = {
   enabled: boolean;
   sources: Array<"memory" | "sessions">;
+  paths: string[];
   provider: "openai" | "local" | "gemini" | "auto";
   remote?: {
     baseUrl?: string;
@@ -162,6 +163,9 @@ function mergeConfig(
     modelCacheDir: overrides?.local?.modelCacheDir ?? defaults?.local?.modelCacheDir,
   };
   const sources = normalizeSources(overrides?.sources ?? defaults?.sources, sessionMemory);
+  // Merge paths from defaults and overrides (both arrays combined, deduped)
+  const pathsSet = new Set<string>([...(defaults?.paths ?? []), ...(overrides?.paths ?? [])]);
+  const paths = Array.from(pathsSet);
   const vector = {
     enabled: overrides?.store?.vector?.enabled ?? defaults?.store?.vector?.enabled ?? true,
     extensionPath:
@@ -236,6 +240,7 @@ function mergeConfig(
   return {
     enabled,
     sources,
+    paths,
     provider,
     remote,
     experimental: {