feat(identity): read claudetools_root from identity.json

- Updated sync.sh to read claudetools_root from identity.json
- Updated syncro.md skill to use identity.json for repo path
- Updated CLAUDE.md onboarding to include claudetools_root field
- Eliminates cross-architecture path detection issues
- Fallback to git rev-parse for legacy machines

Each machine sets claudetools_root during onboarding, just like vault_path.

.claude/CLAUDE.md

@@ -16,10 +16,11 @@ This repo is shared across multiple team members. **At every session start, BEFO
        "email": "mike@azcomputerguru.com",
        "role": "admin",
        "machine": "<HOSTNAME>",
-       "vault_path": "<absolute path to vault repo on this machine>"
+       "vault_path": "<absolute path to vault repo on this machine>",
+       "claudetools_root": "<absolute path to ClaudeTools repo on this machine>"
      }
      ```
-     Ask the user where the vault repo is cloned on this machine (e.g., `D:/vault`, `~/vault`, `/Users/howard/vault`).
+     Ask the user where the vault repo is cloned (e.g., `D:/vault`, `~/vault`, `/Users/howard/vault`) and where ClaudeTools is cloned (e.g., `D:/claudetools`, `~/ClaudeTools`, `/Users/mike/ClaudeTools`).
    - Set local git config: `git config user.name "<full_name>"` and `git config user.email "<email>"`
    - Set git remote (read `gitea_username` from users.json): `git remote set-url origin https://<gitea_username>@git.azcomputerguru.com/azcomputerguru/claudetools.git`
    - Add hostname to user's `known_machines` in users.json and commit.