Release v1.15.1

Fixes for SQL names and user-defined functions:

• Preserve columns named __proto__ in Statement.getAsObject() and Database.each() while keeping ordinary object results.
• Keep aggregate callbacks together so SQL names ending in __finalize cannot collide with another aggregate's internal finalizer.
• Track function registrations by SQLite's ASCII case-insensitive name and argument count, allowing scalar and aggregate overloads to coexist and be replaced independently.

Regression tests reproduce all three failures on the previous implementation. Validation includes the full WebAssembly suite, distribution checks, lint, documentation generation, and the asm.js memory-growth suite.