Necropolitan Cloistered Cleric of Vecna/Divine Oracle 10/Shadowcraft Mage 4/Contemplative 1
Destiny, Knowledge and Tyranny (or Magic) Domains, with Whispered Secrets as your 1st level feat. Fell Conspiracy gives you the ability to make your entire party provide bonuses to listen checks (don't forget to include minions and and provide telepathy, which you could then possibly use to gain access to Mindsight. As a Necropolitan you can pick up Lifesight if Mindsight is not allowed.
Knowledge and Destiny domains are full of scrying abilities and other divinations. Tyranny gives you some nice minion creating abilities through Dominations etc, and you can get some undead minions as well if you need it. Whispered Secrets gives you Spot and Listen, and you've got a Wisdom focus to aid those. Divine Oracle lets you at ECL15 take actions even when surprised.
Shadowcraft Mage and Contemplative can be chosen as you will - Heretic of the Faith lets you decide on whichever Domain you desire, such as those which improve your Skill list (City or Trickery), but skill points are probably beginning to get a bit sparse now.
Alternatively, a Psion, Wilder, Psychic Warrior or Ardent with
Substitute Powers ACF can manifest Sense Danger, a 10 minute/ML duration power, which lets you use one Standard action power as an Immediate Action at the start of each combat (maximum PP of IA power limited to 1+the number of pp augmented Sense Danger).
If your DM is continually springing traps on you, combine with Dominant Mantle Ardent and Linked Power Synchronicity and tell Time Stop to pipe the fuck down as you proceed stab it to death with unlimited PP from Bestow Power and Manifester Arrow hacks.