fix: resolve 25 pre-publish blockers

- postinstall.mjs: fix alias package detection
- migrate-legacy-plugin-entry: dedupe + regression tests
- task_system: default consistency across runtime paths
- task() contract: consistent tool behavior
- runtime model selection, tool cap, stale-task cancellation
- recovery sanitization, context-limit gating
- Ralph semantic DONE hardening, Atlas fallback persistence
- native-skill description/content, skill path traversal guard
- publish workflow: platform awaited via reusable workflow job
- release: version edits reapplied before commit/tag
- JSONC plugin migration: top-level plugin key safety
- cold-cache: user fallback models skip disconnected providers
- docs/version/release framing updates

Verified: bun test (4599 pass), tsc --noEmit clean, bun run build clean

src/hooks/atlas/idle-event.ts

@@ -5,7 +5,7 @@ import {
   readBoulderState,
   readCurrentTopLevelTask,
 } from "../../features/boulder-state"
-import { getSessionAgent, subagentSessions } from "../../features/claude-code-session-state"
+import { getSessionAgent, isAgentRegistered, subagentSessions } from "../../features/claude-code-session-state"
 import { getAgentConfigKey } from "../../shared/agent-display-names"
 import { log } from "../../shared/logger"
 import { injectBoulderContinuation } from "./boulder-continuation-injector"
@@ -141,7 +141,15 @@ export async function handleAtlasSessionIdle(input: {
   if (subagentSessions.has(sessionID)) {
     const sessionAgent = getSessionAgent(sessionID)
     const agentKey = getAgentConfigKey(sessionAgent ?? "")
-    const requiredAgentKey = getAgentConfigKey(boulderState.agent ?? "atlas")
+    const requiredAgentName = boulderState.agent ?? (isAgentRegistered("atlas") ? "atlas" : undefined)
+    if (!requiredAgentName || !isAgentRegistered(requiredAgentName)) {
+      log(`[${HOOK_NAME}] Skipped: boulder agent is unavailable for continuation`, {
+        sessionID,
+        requiredAgent: boulderState.agent ?? "unknown",
+      })
+      return
+    }
+    const requiredAgentKey = getAgentConfigKey(requiredAgentName)
     const agentMatches =
       agentKey === requiredAgentKey ||
       (requiredAgentKey === getAgentConfigKey("atlas") && agentKey === getAgentConfigKey("sisyphus"))
@@ -149,10 +157,10 @@ export async function handleAtlasSessionIdle(input: {
       log(`[${HOOK_NAME}] Skipped: subagent agent does not match boulder agent`, {
         sessionID,
         agent: sessionAgent ?? "unknown",
-        requiredAgent: boulderState.agent ?? "atlas",
-      })
-      return
-    }
+          requiredAgent: requiredAgentName,
+        })
+        return
+      }
   }
 
   const sessionState = getState(sessionID)