Onboarding guide + Howard's own Gitea account + first-time tutorial flow

- ONBOARDING.md: comprehensive guide explaining WHY the setup exists
  (vault, session logs, skills, agents, Ollama/GrepAI, daily workflow).
  Written for someone who's never used Claude Code before.
- CLAUDE.md: on first sync, Claude walks new users through ONBOARDING.md
  section by section + sets up git remote for their own Gitea account.
- users.json: Howard's gitea_username added (own account, admin on all repos).

Audit findings noted: GrepAI not installed, Ollama not running,
MCP_SERVERS.md missing. These need fixing per-machine before onboarding
is fully smooth.

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

.claude/CLAUDE.md

@@ -23,7 +23,12 @@ This repo is shared across multiple team members. **At every session start, BEFO
      git config user.name "<full_name>"
      git config user.email "<email>"
      ```
+   - Set git remote to use the user's own Gitea account (read `gitea_username` from users.json):
+     ```bash
+     git remote set-url origin https://<gitea_username>@git.azcomputerguru.com/azcomputerguru/claudetools.git
+     ```
    - Add the machine hostname to the user's `known_machines` list in `.claude/users.json` and commit.
+   - **IMPORTANT: Show the user `.claude/ONBOARDING.md`** — present it section by section, explain what each part does and WHY, answer any questions. This is their orientation to the system.
 3. **If the hostname doesn't match any known machine** for the identified user, update their `known_machines` in users.json.
 
 ### Session log attribution