feat(memory): native Voyage AI support (#7078)

* feat(memory): add native Voyage AI embedding support with batching

Cherry-picked from PR #2519, resolved conflict in memory-search.ts
(hasRemote -> hasRemoteConfig rename + added voyage provider)

* fix(memory): optimize voyage batch memory usage with streaming and deduplicate code

Cherry-picked from PR #2519. Fixed lint error: changed this.runWithConcurrency
to use imported runWithConcurrency function after extraction to internal.ts

src/config/zod-schema.agent-runtime.ts

@@ -318,7 +318,9 @@ export const MemorySearchSchema = z
       })
       .strict()
       .optional(),
-    provider: z.union([z.literal("openai"), z.literal("local"), z.literal("gemini")]).optional(),
+    provider: z
+      .union([z.literal("openai"), z.literal("local"), z.literal("gemini"), z.literal("voyage")])
+      .optional(),
     remote: z
       .object({
         baseUrl: z.string().optional(),
@@ -338,7 +340,13 @@ export const MemorySearchSchema = z
       .strict()
       .optional(),
     fallback: z
-      .union([z.literal("openai"), z.literal("gemini"), z.literal("local"), z.literal("none")])
+      .union([
+        z.literal("openai"),
+        z.literal("gemini"),
+        z.literal("local"),
+        z.literal("voyage"),
+        z.literal("none"),
+      ])
       .optional(),
     model: z.string().optional(),
     local: z