No trapfinding in Clerical domains
There's a pretty comprehensive list of non-PH Clerical domains at the back of Spell Compendium, and none of these grant trapfinding. I've also checked the Eberron Campaign Setting domains, and there's nothing with trafinding there, either.
The closest matches are Cavern, which grants stonecunning (so you can find stone traps), and Portal, which lets you detect active/inactive portals as if they were normal secret doors.