fix: guard CLI cleanup and DB viewer with wp_presence_has_table()

[aldorizona10-glitch]

What & why

Resolves #210. The WP-CLI cleanup command (includes/cli/class-wp-presence-cli-command.php) and the debug DB viewer (includes/db-viewer.php) were the only two paths that hit the presence table directly without a wp_presence_has_table() check. Every other read/write path in functions.php and the REST controller guards on it and degrades to an empty result, so these two were the last places that would surface a raw wpdb error if the table were ever missing.

As #210 notes, cli_init / admin_init provision the table before either can run, so this is a consistency fix, not a live bug — it was deliberately left out of #203 to keep that change scoped.

Changes

• db-viewer.php — wrap the SELECT / COUNT(*) queries in the availability check; when the table is absent, fall back to an empty row set and a zero count. The template already renders an empty state (No entries.) and the timestamp foreach is empty()-guarded, so no markup changes are needed.
• cli cleanup() — short-circuit to a 0 entries deleted. success before the destructive DELETE (and before the confirmation prompt, since there is nothing to delete).

No new strings, no schema changes, no behavior change on a provisioned site.

Testing

WP-CLI is not loaded in the PHPUnit suite and CLI coverage is being handled separately (#218 / #256), so I've kept this change focused on the guards rather than adding CLI-invoking tests here. Happy to add coverage if you'd prefer a particular approach.

Use of AI Tools

AI assistance: Yes
Tool(s): Claude Code
Model(s): Claude Opus 4.8
Used for: Investigating the guard pattern and drafting the change

[github-actions]

The following accounts have interacted with this PR and/or linked issues. I will continue to update these lists as activity occurs. You can also manually ask me to refresh this list by adding the props-bot label.

Core Committers: Use this line as a base for the props when committing in SVN:

Props aldorza, iamchitti, joefusco.

To understand the WordPress project's expectations around crediting contributors, please review the Contributor Attribution page in the Core Handbook.

[github-actions]

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[codecov]

Codecov Report

❌ Patch coverage is 0% with 3 lines in your changes missing coverage. Please review.
✅ Project coverage is 72.39%. Comparing base (bfb701f) to head (c340132).

❌ Your patch check has failed because the patch coverage (0.00%) is below the target coverage (80.00%). You can increase the patch coverage or adjust the target coverage.

Additional details and impacted files

@@             Coverage Diff              @@
##               main     #257      +/-   ##
============================================
- Coverage     72.51%   72.39%   -0.12%     
- Complexity      175      176       +1     
============================================
  Files            14       14              
  Lines          1819     1822       +3     
============================================
  Hits           1319     1319              
- Misses          500      503       +3     

Flag	Coverage Δ
multisite	72.39% <0.00%> (-0.12%)	⬇️
phpunit	71.07% <0.00%> (-0.12%)	⬇️

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[aldorizona10-glitch]

@i-am-chitti you're right, and apologies for the duplication. I went straight to a PR without commenting on #210 to claim it first, which is exactly what CONTRIBUTING asks — that's on me. Since you called it first and already had it written, I'll close this in favor of your PR. I'll comment to claim before starting next time. Thanks for the nudge.

[i-am-chitti]

Thanks @aldorizona10-glitch for the graceful close. We'd independently landed on almost the same guard, which was oddly reassuring.
Opening mine shortly. Happy for you to be in props on it since you did the same work.