feat: write an agent's presence row when it saves a post - #697

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Props iamchitti, joefusco.

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Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 94.48%. Comparing base (cf96ff1) to head (a92623b).

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+ Coverage     94.46%   94.48%   +0.01%     
  Complexity      270      270              
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  Files            28       28              
  Lines          3942     3951       +9     
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+ Hits           3724     3733       +9     
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Using wp_presence_idle_threshold() for the expiry means the row follows a site's filtered Heartbeat interval, and the README now matches how agents actually show up.

A few questions from running it locally. wp_insert_post( array( 'post_status' => 'auto-draft' ) ) returns 0 because core treats it as empty content, so the auto-draft test passes with or without the guard. Would a post_title there make it catch that? Revisions don't support presence either, so wp_presence_post_room() seems to return false for revisions and autosaves before the new checks run. Could the handler lean on that and drop those checks and their test, or is there a case you had in mind where they'd matter? The refresh test also caught nothing the others didn't, since wp_set_presence() rewrites the row on every save. What do you see it guarding?

I'm also curious about trash. Moving a post to the trash fires wp_after_insert_post, so an agent that trashes a post gets a fresh row in that room. Does that fit how you picture agent presence?

I've moved my questions from yesterday into #698 so they don't hold this up. None of them change what ships here.