feat(hooks): add sisyphus-junior-notepad hook for conditional notepad rules injection (#1092)

* refactor(shared): extract isCallerOrchestrator to session-utils

* refactor(atlas): use shared isCallerOrchestrator, change to prepend

* refactor(prometheus-md-only): change to prepend pattern

* refactor(sisyphus-junior): remove Work_Context (moved to hook)

* feat(hooks): add sisyphus-junior-notepad hook

* fix(shared): replace dynamic require with static import in session-utils

- Change from dynamic require to static import for better bundler compatibility
- Fix import path: ../../features -> ../features
- Add barrel export to src/shared/index.ts

* feat(hooks): register sisyphus-junior-notepad hook

- Add to HookNameSchema in schema.ts
- Export from hooks/index.ts
- Register with isHookEnabled in index.ts
- Auto-generated schema.json update

---------

Co-authored-by: justsisyphus <justsisyphus@users.noreply.github.com>

src/shared/session-utils.ts

@@ -0,0 +1,27 @@
+import * as path from "node:path"
+import * as os from "node:os"
+import { existsSync, readdirSync } from "node:fs"
+import { join } from "node:path"
+import { findNearestMessageWithFields, MESSAGE_STORAGE } from "../features/hook-message-injector"
+
+export function getMessageDir(sessionID: string): string | null {
+  if (!existsSync(MESSAGE_STORAGE)) return null
+
+  const directPath = join(MESSAGE_STORAGE, sessionID)
+  if (existsSync(directPath)) return directPath
+
+  for (const dir of readdirSync(MESSAGE_STORAGE)) {
+    const sessionPath = join(MESSAGE_STORAGE, dir, sessionID)
+    if (existsSync(sessionPath)) return sessionPath
+  }
+
+  return null
+}
+
+export function isCallerOrchestrator(sessionID?: string): boolean {
+  if (!sessionID) return false
+  const messageDir = getMessageDir(sessionID)
+  if (!messageDir) return false
+  const nearest = findNearestMessageWithFields(messageDir)
+  return nearest?.agent?.toLowerCase() === "atlas"
+}