merge: integrate origin/dev into modular-enforcement branch

Resolves all merge conflicts, preserving our split module structure
while integrating all dev changes:
- Custom agent summaries support (parseRegisteredAgentSummaries)
- Background notification queue (enqueueNotificationForParent)
- Atlas shared git-worktree module (collectGitDiffStats, formatFileChanges)
- Ralph-loop withTimeout + DEFAULT_API_TIMEOUT=5000
- Session recovery assistant_prefill_unsupported error type
- Atlas agentOverrides forwarding
- Config handler plan model demotion (buildPlanDemoteConfig)
- Delegate-task agentOverrides, promptSyncWithModelSuggestionRetry, variant
- LSP init timeout + stale init detection
- isPlanFamily function + task-continuation-enforcer hook
- Handoff command

src/tools/delegate-task/sync-prompt-sender.ts

@@ -1,6 +1,6 @@
 import type { DelegateTaskArgs, OpencodeClient } from "./types"
-import { isPlanAgent } from "./constants"
-import { promptWithModelSuggestionRetry } from "../../shared"
+import { isPlanFamily } from "./constants"
+import { promptSyncWithModelSuggestionRetry } from "../../shared"
 import { formatDetailedError } from "./error-formatting"
 
 export async function sendSyncPrompt(
@@ -16,8 +16,8 @@ export async function sendSyncPrompt(
   }
 ): Promise<string | null> {
   try {
-    const allowTask = isPlanAgent(input.agentToUse)
-    await promptWithModelSuggestionRetry(client, {
+    const allowTask = isPlanFamily(input.agentToUse)
+    await promptSyncWithModelSuggestionRetry(client, {
       path: { id: input.sessionID },
       body: {
         agent: input.agentToUse,