refactor: change data directory from .coin-hunter to .coinhunter

- Update SKILL.md references to use ~/.coinhunter/
- Update user-data-layout.md with new directory paths
- Update init_user_state.py ROOT path
- Unify naming convention with .stockbuddy style

references/user-data-layout.md

@@ -1,13 +1,13 @@
 # User Data Layout
 
-Store private coin-hunter data outside the skill directory.
+Store private coinhunter data outside the skill directory.
 
 ## Root directory
 
 Use:
 
 ```text
-~/.coin-hunter/
+~/.coinhunter/
 ```
 
 This keeps personal accounts, positions, and watchlists out of packaged skill artifacts.
@@ -15,7 +15,7 @@ This keeps personal accounts, positions, and watchlists out of packaged skill ar
 ## Layout
 
 ```text
-~/.coin-hunter/
+~/.coinhunter/
 ├── config.json
 ├── accounts.json
 ├── positions.json
@@ -136,8 +136,8 @@ Store disposable API results or normalized snapshots. Never treat this as source
 
 ## Rules
 
-- Keep personal data only under `~/.coin-hunter/`
-- Never write personal account or position data into `skills/coin-hunter/`
+- Keep personal data only under `~/.coinhunter/`
+- Never write personal account or position data into `skills/coinhunter/`
 - Treat `cache/` as disposable
 - Prefer stable IDs for accounts like `bybit-main`
 - For meme coins, include `chain` and `contract_address` when known