
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
Given the ellipse $E$: $\frac{x^{2}}{a^{2}} + \frac{y^{2}}{b^{2}} = 1 (a > b > 0)$, its eccentricity is $\frac{\sqrt{2}}{2}$, point $F$ is the left focus of the ellipse, point $A$ is the right vertex, and point $B$ is the upper vertex. Additionally, $S_{\triangle ABF} = \frac{\sqrt{2}+1}{2}$.
(I) Find the equation of the ellipse $E$;
(II) If the line $l$: $x - 2y - 1 = 0$ intersects the ellipse $E$ at points $P$ and $Q$, find the perimeter and area of $\triangle FPQ$.

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