fix(delegate-task): remove kimi from unstable agent detection, harden callID resolution for metadata store

- Remove kimi from auto-detected unstable agents in category-resolver (only gemini/minimax remain)
- Add resolveCallID() to safely resolve callID/callId/call_id variants from tool context
- Use resolveCallID across all 5 delegate task execution paths (sync, background, unstable, continuations)
- Update writing category test to verify kimi runs sync when kimi provider is available
- Add atlas metadata preservation tests confirming tool-execute-after does not clobber metadata

Co-authored-by: factory-droid[bot] <138933559+factory-droid[bot]@users.noreply.github.com>

src/tools/delegate-task/sync-continuation.ts

@@ -2,6 +2,7 @@ import type { DelegateTaskArgs, ToolContextWithMetadata } from "./types"
 import type { ExecutorContext, SessionMessage } from "./executor-types"
 import { isPlanFamily } from "./constants"
 import { storeToolMetadata } from "../../features/tool-metadata-store"
+import { resolveCallID } from "./resolve-call-id"
 import { getTaskToastManager } from "../../features/task-toast-manager"
 import { getAgentToolRestrictions } from "../../shared/agent-tool-restrictions"
 import { getMessageDir } from "../../shared"
@@ -78,8 +79,9 @@ export async function executeSyncContinuation(
       },
     }
     await ctx.metadata?.(syncContMeta)
-    if (ctx.callID) {
-      storeToolMetadata(ctx.sessionID, ctx.callID, syncContMeta)
+    const callID = resolveCallID(ctx)
+    if (callID) {
+      storeToolMetadata(ctx.sessionID, callID, syncContMeta)
     }
 
     const allowTask = isPlanFamily(resumeAgent)