fix: harden balance type-safety and precision handling (closes #227)

[Mosas2000]

Summary

This PR resolves issue #227 by eliminating unsafe balance handling patterns and enforcing integer-safe micro-STX logic across hooks, utilities, and tip form validation.

What changed

• now normalizes API balance values to canonical non-negative integer micro-STX strings.

• Added precision-safe utilities in :
• Updated and to use integer-safe balance sufficiency checks instead of float comparisons.
• Hardened formatting path for very large balances.

• Expanded regression coverage in:
• Added changelog entry documenting the fix.

Verification

• Ran targeted test suite:

RUN v3.2.4 /Users/macosbigsur/Documents/Code/Stacks-project/TipStream

• Result: 3 test files passed, 115 tests passed.

Notes

• This branch intentionally preserves a granular history with 27 commits, as requested.

Closes #227