Flatten cases directory structure and unify paths

- Remove cases/new|in-progress|completed subdivision (status managed in DB)
- Rename documents/original → documents/originals (consistent plural)
- Move exports from global data/exports/ into cases/{num}/exports/
- Add documents/research/ for case law and analysis files
- Update all agents, scripts, config, web API endpoints, and DB paths

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

CLAUDE.md

@@ -79,8 +79,8 @@
 │   └── docx/                             עיצוב DOCX
 ├── data/
 │   ├── training/                      ← 4 החלטות לאימון (DOCX)
-│   ├── uploads/                       ← קבצים מ-web UI
-│   └── cases/{new,in-progress,completed}/ ← תיקי עררים
+│   ├── exports/                       ← ייצוא legacy (תיקים ישנים)
+│   └── cases/{case-number}/           ← תיקי עררים (מבנה שטוח, סטטוס ב-DB)
 ├── web/                               ← UI + API + integration clients
 ├── mcp-server/                        ← MCP server + services + tools
 └── scripts/                           ← סקריפטים וכלי עזר