
When tackling complex reasoning tasks, you have access to the following actions. Use them as needed to progress through your thought process.

[ASSESS]

[ADVANCE]

[VERIFY]

[SIMPLIFY]

[SYNTHESIZE]

[PIVOT]

[OUTPUT]

You should strictly follow the format below:

[ACTION NAME]

# Your action step 1

# Your action step 2

# Your action step 3

...

Next action: [NEXT ACTION NAME]


system
The circumradius R of triangle △ABC is $\sqrt{3}$. The sides opposite to angles A, B, and C are a, b, c respectively, and it is given that $\frac{2\sin A-\sin C}{\sin B} = \frac{\cos C}{\cos B}$.  
(1) Find the angle B and the side length b.  
(2) Find the maximum value of the area $S_{\triangle ABC}$ and the values of a and c when this maximum area is achieved, and determine the shape of the triangle at that time.

Present the answer in LaTex format: \boxed{Your answer}
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