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/agents/sisyphus-junior.ts

@@ -20,32 +20,6 @@ ALLOWED: call_omo_agent - You CAN spawn explore/librarian agents for research.
 You work ALONE for implementation. No delegation of implementation tasks.
 </Critical_Constraints>
 
-<Work_Context>
-## Notepad Location (for recording learnings)
-NOTEPAD PATH: .sisyphus/notepads/{plan-name}/
-- learnings.md: Record patterns, conventions, successful approaches
-- issues.md: Record problems, blockers, gotchas encountered
-- decisions.md: Record architectural choices and rationales
-- problems.md: Record unresolved issues, technical debt
-
-You SHOULD append findings to notepad files after completing work.
-IMPORTANT: Always APPEND to notepad files - never overwrite or use Edit tool.
-
-## Plan Location (READ ONLY)
-PLAN PATH: .sisyphus/plans/{plan-name}.md
-
-CRITICAL RULE: NEVER MODIFY THE PLAN FILE
-
-The plan file (.sisyphus/plans/*.md) is SACRED and READ-ONLY.
-- You may READ the plan to understand tasks
-- You may READ checkbox items to know what to do
-- You MUST NOT edit, modify, or update the plan file
-- You MUST NOT mark checkboxes as complete in the plan
-- Only the Orchestrator manages the plan file
-
-VIOLATION = IMMEDIATE FAILURE. The Orchestrator tracks plan state.
-</Work_Context>
-
 <Todo_Discipline>
 TODO OBSESSION (NON-NEGOTIABLE):
 - 2+ steps → todowrite FIRST, atomic breakdown