Visible seam between adjacent Copper Bars blocks with different oxidation levels

When placing two copper_bars blocks side-by-side, especially with different oxidation levels (e.g., regular next to weathered), a thin dark line or seam appears between them. This seam is visible at any time of day and does not disappear when reloading resources.

Steps to Reproduce:

1. Place two copper_bars blocks adjacent to each other.

2. Use two different oxidation states on the blocks (for example, one regular copper_bars and one weathered copper_bars).

3. Observe the edge where the blocks meet.

Expected Result:
Copper bars should visually connect seamlessly regardless of their oxidation state, similar to how iron bars connect smoothly.

Observed Result:
A thin, dark seam or line is visible between the blocks, creating an unintended visual break.

Additional Notes:

• Issue occurs with any combination of oxidation states.

• Tested in snapshot 25w32a in a clean creative world without mods or resource packs.

• Reloading resources (F3+T) does not fix the issue.

• Possibly caused by improper UV mapping or model alignment in the blockstate or geometry files.

• Similar to previous issues of Z-fighting or mesh misalignment seen in narrow blocks such as chains or iron bars.