fix: *.Int64() -> safeConvertToInt64()

[notJoon]

Description

Use safe type conversion

[dongwon8247]

Can you check these additional points?

1. POOL

• position.gno:122,127 - u256.MulDiv(...) for fee calculations (fee overflow)

2. POSITION (String parsing issues)

• mint.gno:261,270 - mustParseInt64(amount0Desired)
• Large amounts fail to parse

3. X96/X128 Operations Needing Protection
   All these MulDiv operations need overflow checks:

• Pool fee growth: swap.gno:434
• Position fees: position.gno:122,127
• Liquidity calculations: Multiple files
• Reward calculations: reward_manager.gno:119

[notJoon]

Can you check these additional points?

@dongwon8247
trying to resolve them in this PR #816

For the mustParseInt64 function, a parameter value of 9.2 * 10^18 or greater would need to be passed. However, when passing such a value through gnokey as an entry function, the input itself is impossible, and since it's only used for native token wrapping, there would be no problem unless the user actually possesses that amount of tokens.

[sonarqubecloud]

Quality Gate passed

Issues
10 New issues
0 Accepted issues

Measures
0 Security Hotspots
0.0% Coverage on New Code
0.0% Duplication on New Code

See analysis details on SonarQube Cloud