[lua] Fix Kumhau the Flashfrost Naakual cutscene exit position

[Millhouse1337]

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• I have tested my code and the things my code has changed since the last commit in the PR and will test after any later commits.

What does this pull request do?

Closes #7234.

The X coordinate of the post-cutscene setPos call in SoA mission 3-6-1 (Kumhau, the Flashfrost Naakual) was missing its negative sign. After the cutscene at event 27 finishes, the player is teleported to (344.003, 40.676, -381.140) in Kamihr Drifts, which lands them out-of-bounds. The intended location is (-344.003, 40.676, -381.140).

This PR adds the missing minus sign so the player lands at the intended spot.

Steps to test these changes

In Kamihr Drifts (zone 267), with GM rights:

1. !pos 344.003 40.676 -381.140 267 — observe player is teleported out-of-bounds (into sky/void area), reproducing the bug.
2. !pos -344.003 40.676 -381.140 267 — observe player lands on solid, walkable terrain inside the zone, confirming the fix.

Verified locally — buggy coordinates land in a void, fixed coordinates land on solid Kamihr Drifts terrain.

[WinterSolstice8]

do you have a cap for this?

[Millhouse1337]

No cap, just went by the value cited in #7234 (-344.0043) and tested in-game:

• 344.003 lands the player out of bounds.
• -344.003 lands them on walkable Kamihr Drifts terrain.

Happy to hold this if someone wants to confirm with a cap. @sruon do you have one?

[siknoz]

its close enough maybe, actual coord is

-344.002, 040.675, -381.140 which compared to
-344.003, 040.676, -381.140

Cap:
https://youtu.be/GoltLTLYw5o?si=7BGqSdeRYjpVY3Ec&t=1526