docs: add gas optimization guide to Network Information – actionable patterns for Base builders with examples using viem.

[khang8473]

What changed? Why?

• Base builders frequently ask about practical ways to reduce gas costs and improve UX, especially for high-frequency apps, agents, consumer mini-apps, and account abstraction flows. While general Ethereum gas optimization resources exist, they miss Base-specific nuances (Flashblocks, sequencing behavior, fee estimation patterns, public RPC characteristics, and L2-specific gotchas).

• This fills a clear gap without overlapping existing pages. It provides immediately actionable, copy-paste-ready examples using modern tools (viem, etc.) that align with the rest of the docs.

• Improves developer experience for both new and experienced teams, supporting Base’s goal of being the easiest L2 to build on.

• Timely with recent network improvements (Azul, performance gains, Flashblocks rollout).

[cb-heimdall]

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